Spirit of Arachyr has been one of the weakest and most clunky sets in the game for quite some time, being completely outclassed for years. Despite being forgotten, it has been the Trash Killer of choice from Season 7 to 9 using Firebats due to its insane Attack Speed and density scaling.
But Season 25 finally brings us a rework to the (2) & (4) Bonuses of the set in order to create a unique generator playstyle using Corpse Spiders. In addition Corpse Spiders now act as Pets, benefitting from Pet damage multipliers such as Enforcer and Mask of Jeram.
While The Spider Queen's Grasp only got a new damage multiplier, the new Brood of Araneae provides a unique damage stacking mechanic. At the same time, Lakumba's Ornament and Shukrani's Triumph have been reworked, bringing new tools for the Witch Doctors to play with.
During Season 25, Soul Shards with the amazing combination of Dregs of Lies and Sliver of Terror created an interesting burst playstyle for the build. In Season 27, a specific LoD Corpse Spiders setup (see Variants) made it into the spotlight and turned out to be an incredible Rift Guardian Killer. Unfortunately, Season 30 crushed the potential of the build, cutting by more than half the (6) Bonus damage multiplier.
While the build works with Area Damage (AD), since Corpse Spiders can proc it, Arachyr (2) Bonus spread damage mechanic unfortunately does not proc it which makes it a not-so-desirable stat to stack. However the build has an incredible scaling with Attack Speed due to Brood of Araneae and relies on intricate interactions due to Corpse Spiders being Pets (see Mechanics). This build offers a very unique playstyle with a good balance between AoE and single target damage and is a decent all-rounder for all kinds of activities. From now on, you're going to like spiders!
High DPS ✔ Fun to Play ✔ Unique Playstyle ✔ Easy to Get Starter Gear ✔
❌ Lack of Mobility ❌ Positioning is Critical ❌ Frustrating Pet Targeting ❌ Vulnerable to Crowd Control
Core Setup
Items
Spirit of Arachyr provides us with a 11,500% damage multiplier for Corpse Spiders as well as a tremendous 75% damage reduction alongside a Spider Queen and a spread damage mechanic for Corpse Spiders.
The Spider Queen's Grasp is purely utilized for its 800% separate damage multiplier for Corpse Spiders.
Brood of Araneae provides us with a 100% damage multiplier and another multiplier in the form of a damage stacking mechanic.
Mask of Jeram increases all Pet damage by 200%. This effect is additive with Elemental damage on Bracers and Amulet.
Depth Diggers gives us another 100% damage boost on our main skill Corpse Spiders.
Lakumba's Ornament provides us with another 70% damage reduction with Soul Harvest Languish which already gives us 15% Intelligence and 50% Armor.
Ring of Emptiness provides us with a crazy 300% damage buff as long as the target is affected by either Haunt or Locust Swarm.
Shukrani's Triumph grants us a 100% additive damage buff while using Spirit Walk which perfectly complements our playstyle.
Echoing Fury is used for an insane 75% Attack Speed bonus which double dips thanks to Brood of Araneae.
Season 33 Shades of the Nephalem
For the duration of Season 33, you gain one extra slot in Kanai’s Cube that allows to choose any Legendary Powers for a total of 4 slots. While normally a player can equip one power each from the Weapon, Armor, and Jewelry categories, now you can add a second of one of these categories! Some builds enjoy major damage buffs while others are able to run completely different setups, for example through otherwise impossible combinations of weapon effects.
In addition, whenever you press a shrine or pylon, you spawn a Shadow Nephalem of your class to assist you for 1 minute. These use various abilities and provide helpful extra damage in the early game and for lower tier Greater Rifts. Learn more in our Season 22 overview.
In this build, depending on the setup you can gain a free The Furnace or Echoing Fury to maximize damage.
Global Stat Priorities
You want to stack damage stats wherever possible, especially Attack Speed, Critical Hit Chance and Damage as well as Corpse Spiders Damage. Physical Damage is always a decent damage stat but its value is significantly decreased due to Mask of Jeram being additive with Elemental Damage. Area Damage works with Spiders but is not a priority because it does not work with Spirit of Arachyr(2) Bonus.
Make sure to focus on Attack Speed to reach a high Breakpoint. It is the most important stat to stack for this build as Corpse Spiders in combination with Brood of Araneae benefit twice from it (see Mechanics).
Cooldown Reduction is not really needed as Grave Injustice does all the work, especially with some Pickup Radius. It is still a good defensive stat to get on items lacking good offensive options like Shoulders.
Crowd Control Reduction is an incredibly valuable secondary Affix to roll on both Rings, Amulet and Helmet as we are very sensitive to Hard Crowd Control effects and mitigating these will ease up our gameplay significantly. Make sure to get the Primary Affixes locked in before attempting to get CCR though.
Assembling the Build
1. Do the Challenge Rift for the materials to cubeLegendary Powers. You can complete this once a week for additional resources and we always update the guide for you!
2. Gather the full Spirit of Arachyr set. Each piece can be gambled from Kadala for Bloodshards. Do not salvage any duplicate pieces you find! Instead convert them to another part of the set with Recipe 4 in Kanai's Cube. If you have extra materials you can use Recipe 3 to craft the remaining pieces, but this is expensive and not recommended for new players.
Rings to get Ring of Emptiness and The Compass Rose
Amulets to get The Traveler's Pledge
Anything from the Gamble list in Step 3 that you haven't already acquired.
5. Do Bounties to acquire several important items for this build:
Act 1: Ring of Royal Grandeur
Bounty Turn In: Recipe for Cain's Destiny and Captain Crimson's Trimmings (for your follower)
6. At this point you can somewhat comfortably farm Nephalem or Speed Greater Rifts where you can find all the remaining items you need for different variants of the build. Spend your materials getting items with better rolls and/or ancient quality.
7. Use Primordial Ashes in Kanai's Cube with the new Curiosity of Lorath Nahr recipe to obtain a free Crafted Primal Ancient. Since you can only equip one of them, choosing the right item to focus matters! Great candidates are Weapons, Offhands, Jewelry or any item with an important multiplier. With that in mind, we recommend getting one of the following items:
The Spider Queen's Grasp
Ring of Emptiness
Shukrani's Triumph
The Compass Rose
Item Stat Priorities
SLOT
ITEM
STAT PRIORITY
Main-Hand
The Spider Queen's Grasp Echoing Fury (Cubed) Wormwood (Cubed) The Furnace (Cubed)
1. Damage Range 2. Socket Ramaladni's Gift 3. Attack Speed 4. Damage % 5. Intelligence
Off-Hand
Shukrani's Triumph
1. Critical Hit Chance 2. Corpse Spiders Damage 3. Elite Damage 4. Intelligence 5. Cooldown Reduction 6. Vitality
1. Socket 2. Critical Hit Damage 3. Critical Hit Chance 4. Physical Damage 5. Attack Speed 6. Intelligence
Belt
Brood of Araneae
1. Corpse Spiders Damage 2. Intelligence 3. Vitality 4. Armor 5. Life % 6. All Resistance
Potion
Bottomless Potion of the Unfettered
To avoid Crowd Control effects during your DPS phases
Gems
Simplicity's Strength is a mandatory gem as it provides us with a 100% separate damage multiplier and great Life recovery with our Corpse Spiders.
Enforcer is strictly better than Bane of the Trapped since its damage multiplier is unconditional and all our damage comes from Corpse Spiders.
Bane of the Trapped grants us a global separate 1.6 damage multiplier. Spirit of Arachyr Webs and The Spider Queen's Grasp continuously apply slows to proc it.
Bane of the Stricken helps us kill the Rift Guardian. As long as you don't need more than 2 minutes to kill it you can equip Bane of the Trapped instead. This is only necessary for RGK setups.
For Nephalem Rifts, Boon of the Hoarder is always a default include specifically due to its amazing synergy with Avarice Band.
Skills
We use Corpse Spiders as our main damage dealer. Widowmakers is preferred due to its slightly higher raw damage compared to other runes.
Locust Swarm is mandatory in order to proc our Ring of Emptiness massive damage multiplier.
Piranhas Piranhado is used to apply a 15% additive damage debuff and pull enemies together. Keep in mind you need to kill monsters to reset its cooldown with Grave Injustice.
Spirit Walk Jaunt or Severance for mobility and survival purposes as well as a damage cooldown with Shukrani's Triumph.
Soul Harvest Languish for massive damage and damage reduction buffs with Lakumba's Ornament.
Horrify Frightening Aspect for a permanent 50% Armor buff. At higher Paragon, this can be swapped with Big Bad Voodoo Slam Dance in combination with Grave Injustice for 15% Attack Speed and Additive Damage which is the best damage output option.
Passives
Grave Injustice is the cornerstone of our playstyle. It reduces cooldowns when you kill enemies, allowing a very high uptime of Spirit Walk.
Pierce the Veil is a 20% additive damage buff at the expense of increased Mana costs. As this is a Generator build with Corpse Spiders the latter does not matter.
Confidence Ritual is a staple for its 25% separate damage multiplier.
Spirit Vessel as a cheat death mechanic because dying always sucks, right? Swampland Attunement is also a great option for defensive purposes.
If you feel brave enough to get rid of a pure defensive passive, Gruesome Feast is always a pretty good option for more offense and defense.
Paragon Points
Core
Offensive
Defensive
Utility
1. Movement Speed
1. Attack Speed
1. Armor
1. Pickup Radius
2. Intelligence
2. Critical Hit Damage
2. Life %
2. Life per Hit
3. Vitality1
3. Critical Hit Chance
3. All Resistance
3. Area Damage
4. Maximum Mana
4. Cooldown Reduction
4. Life Regeneration
4. Resource Cost Reduction
1 Add a bit of Vitality if you feel too squishy (a total of 700,000 Life is recommended).
Altar of Rites
The Altar of Rites is a tree that grants tremendous powers to your entire account in exchange for sacrifices. It requires you to farm Bounties, kill the Ubers, craft the Staff of Herding, and more. Completing all 26 of these tasks, along with sacrificing 6 Primal Ancients grants you extra Damage, Defense, Quality of Life, Increased Drops and 3 Potion Super Powers. Read the full guides on Unlocking the Altar and the Altar Mechanics by Raxxanterax and Chewingnom to learn everything about this fantastic mechanic!
Note: The suggested path assumes you are playing Solo and used the Challenge Rift Cache to help you level up.
Optimal Path
Node 2: Choose Anointed to gain a full set of 70 yellows from level 18-70!
Node 6: Rush to gain double Bounties to help unlock other Nodes in the Altar.
Nodes 7-14: These are the last Nodes you can gain until the Challenge Rift resets. Take at least 1 Node at the bottom of each path to unlock all 3 Potion Super Powers. Pick up the Mirror Node at the top for a colossal 41% extra XP all season. Remember to unlock Father once you clear GR70 solo and have your first Primal!
Nodes 15-26: Pick up the final Quality of Life, Damage, and Defense Nodes (in that order) to finish the Altar.
Potion Super Powers: Take Father first, then Mother, and finally Mortal.
Disclaimer: The Mortal and Mother Potions require you to salvage 2 and 3 Primals respectively. Unlock them as soon as you have those materials as they don't cost a point!
Follower
Patch 2.7.0 revamped the follower system giving all 3 hirelings new powers and the emanate system. The first thing you should do is read our complete follower guide and remember the key takeaways:
The emanation system allows followers to share certain legendary and set powers with you. The most important ones are: The Flavor of Time, Nemesis Bracers, Avarice Band, Sage’s Journey and Cain’s Destiny. Click the guide above for the full list.
Follower’s powers are based on their main stat (maxed at 25,000, but they have a 2.5x multiplier so you only need 10,000). This means we stack Intelligence on the Enchantress, Dexterity on the Scoundrel and Strength on the Templar.
Guardian's Jeopardy(3) Bonus works for followers by improving their inherent stat multiplier from x2.5 to x3.5, making it slightly easier to hit the 25,000 main stat threshold if needed.
Followers share 20% of their Experience, Magic and Gold Find stats with you.
Legendary gems do not work on followers, except Esoteric Alteration and Mutilation Guard.
With Enforcer equipped on the player, it is much easier to keep followers alive without immortality relic since the 90% damage reduction works on them.
Cooldown Reduction does not work for any follower skill except the Templar’s Heal.
Followers never deal significant damage; you’re on your own to clear the content.
Select Follower
T16 Enchantress
For T16 we recommend this Enchantress setup because she is the only follower that gives Cooldown Reduction, allowing you to spam your abilities more. Since this is T16 content, she’ll stay alive with Esoteric Alteration and Mutilation Guard and use Hand of the Prophet to gain all skills. This will give us Cooldown Reduction, Elemental Damage, Reduced Damage from Ranged Attacks, Armor, Attack Speed, and a Cheat Death. Stat Priorities:Since we do not have the immortality focus, we need to stack survivability on our Enchantress.
Intelligence > Vitality > Life % > Armor > All Resistance > Life Per Hit > Attack Speed.
Key Items:
The Flavor of Time: For double duration on Pylons.
Nemesis Bracers: For extra Elites, Death’s Breaths and In-geom procs.
Avarice Band: For the insane pickup radius.
Ring of Royal Grandeur: To complete our sets.
Gloves of Worship: For 10 Minute Shrine Buffs.
Sage’s Journey: For double Death’s Breaths.
Cain’s Destiny: For 25% more Greater Rift Keystones.
For Greater Rift we recommend this Enchantress setup because she is the only follower that gives Attack Speed, which double dips. She’ll stay alive because we have Enforcer with Esoteric Alteration and Mutilation Guard and use Hand of the Prophet to gain all skills. This will give us Attack Speed, Cooldown Reduction, Elemental Damage, Reduced Damage from Ranged Attacks, Armor, and a Cheat Death.
Stat Priorities:Since we do not have the immortality focus, we need to stack survivability on our Enchantress.
Intelligence > Vitality > Life % > Armor > All Resistance > Life Per Hit > Attack Speed.
Key Items:
The Flavor of Time: For double duration on Pylons.
Nemesis Bracers: For more progression from Elites.
Oculus Ring: For 85% increased damage.
Blind Faith: To consistently blind the Rift Guardian, helping with Squirt's Necklace.
Ice Climbers: To make your follower immune to Freeze and Immobilize effects.
The Witching Hour, Tal Rasha's Relentless Pursuit and Cain's Destiny: For more Attack Speed.
Gameplay
When you enter a Greater Rift, start off by using Spirit Walk to run towards enemies and use Horrify Frightening Aspect and Soul Harvest to get your defensive buffs. Never let them drop! Then start to gather monsters with Corpse Spiders and Locust Swarm.
Use Spirit Walk to move through enemies that are in the way, for defense, to dodge affixes and projectiles or similar. Don't waste it when you don't need it! When making a pull, engage several screens of monsters by bodypulling and casting Locust Swarm, then group them up using Piranhas Piranhado.
When you are ready to damage monsters:
Make sure you infest most enemies for the (2) Bonus spread damage which constitutes most of your AoE damage. To do so, you need to hit them with the Thread between you and your ArachyrSpider Queen. Making a quick circle around the pull while the Spider Queen is in the middle of it is a good way to infest most enemies in the blink of an eye. Remember that you can position her at will by throwing Corpse Spiders at that location.
Focus an Elite and throw Corpse Spiders onto it.
If you get an Oculus Ring spawn near you, you can quickly get inside while throwing jars.
Use Spirit Walk wisely to damage burst with Shukrani's Triumph.
On Rift Guardians:
Make sure to infest the Rift Guardian since the Arachyr (2) Bonus works even on the target you're dealing damage to, meaning it doubles your damage output in single target.
On Bloodmaw, use Spirit Walk whenever the Rift Guardian starts its Leap animation. This interrupts it as Bloodmaw needs to have a target to perform this attack.
On Voracity, use Spirit Walk while entering Gas Clouds. As AoE ground effects snapshot toughness upon entering them, you will take 0 damage from the Gas Clouds.
Use the layout to protect yourself from some Rift Guardians' abilities like on Agnidox, Cold Snap or Erethon. Check out this post about Rift Guardians to learn more!
Hardcore
This build is pretty tanky by default. For extra safety you can swap Echoing Fury with Sacred Harvester at the expense of significant damage. Don't forget to play with Spirit Vessel. You should also take the cheat death proc on your follower for extra safety. Check out our dedicated Hardcore Survival Guide to learn more about how to succeed in this game mode!
Variants
Nephalem Rifts
GR Solo Speeds
GR Solo Push
GR Group RGK
Echoing Nightmare
Concept In this setup we focus mainly on Movement Speed and some Cooldown Reduction. We have awesome Spirit Walk uptime as we are constantly killing enemies with Grave Injustice synergizing with Shukrani's Triumph. We add Molten Wildebeest's Gizzard to protect our Squirt's Necklace for double damage.
Gameplay Cast Summon Zombie Dogs once at the beginning to create minions for your Fierce Loyalty; simply spam-click Horrify, Spirit Walk and Soul Harvest off cooldown. Locust Swarm Pestilence is automatically cast thanks to Wormwood.
Horrify in conjunction with Rechel's Ring of Larceny provides you with an incredible amount of Movement Speed, effectively making you fly through Nephalem Rifts while Boon of the Hoarder and Avarice Band (on your follower) allow you to pick up Progress Globes instantly.
Setups In groups, swap out Warzechian Armguards and Ring of Emptiness for Nemesis Bracers and Avarice Band.
Concept We have awesome Echoing Fury and Spirit Walk uptime as we are constantly killing enemies with Grave Injustice. We take Molten Wildebeest's Gizzard to protect our Squirt's Necklace for double damage.
The idea is to farm a Greater Rift tier where you can comfortably clear within 3 to 4 minutes. The gameplay is simply a sped up variant of the solo push one.
Gameplay Keep up your Horrify Frightening Aspect and Soul Harvest buffs at all times. Create huge pulls with Piranhas Piranhado and group them tightly for heavy Infest Damage from the (2) Bonus.
Setups At lower Paragon (below 1,000) Piranhas can be replaced with Summon Zombie Dogs Leeching Beasts for insane recovery. Also feel free to change Confidence Ritual to Spirit Vessel for better survivability.
Select Build Version
Echoing Fury Setup
Concept Spirit of Arachyr uses the amazing pull from Piranhas Piranhado and combines it with the strong single target of Corpse Spiders spread through the (2) Bonus. As usual, Grave Injustice grants this setup a nice uptime on all its cooldowns. Bane of the Stricken is not mandatory to kill the Rift Guardian.
Gameplay Keep up your Soul Harvest and use Spirit Walk to skip bad map layouts, dodge attacks and projectiles, and to perform damage bursts with Shukrani's Triumph. DoT up enemies with your Locust Swarm to ensure the damage buff from Ring of Emptiness is active. Cast Piranhas Piranhado to group up enemies, infest them with the thread between you and your Spider Queen, select your target and start spamming Corpse Spiders. For a step-by-step gameplay description on how you should sequence your skills, check out the "Gameplay" section above.
Setups At lower Paragon, Piranhas can be replaced with Summon Zombie Dogs Leeching Beasts for insane recovery. On the contrary, at higher Paragon you can replace Horrify with Big Bad Voodoo for more damage. Also feel free to change Pierce the Veil to Spirit Vessel for better survivability. Alternatively, you can replace Echoing Fury with Sacred Harvester at the cost of significant damage.
Concept The other variant you might find on the leaderboards is the Wormwood one taking advantage of one additional skill slot to grab Big Bad Voodoo with either Jungle Drums or Slam Dance. You are abit tankier and have less things to manage since you do not have to care about applying Locust Swarm yourself for Ring of Emptiness bonus.
Please note that this setup is not the strongest out there. The playstyle is similar to the regular version, except you are tankier and have a much smoother playstyle as you do not need to selfcast Locust Swarm. However the damage burst potential from the other setup with Echoing Fury Attack Speed stacks pulls ahead of this one by around 2 tiers.
Setups At lower Paragon, Piranhas can be replaced with Summon Zombie Dogs Leeching Beasts for insane recovery. On the contrary, at higher Paragon you can replace Horrify with Big Bad Voodoo for more damage. Also feel free to change Pierce the Veil to Spirit Vessel for better survivability. Alternatively, you can replace Wormwood with Sacred Harvester at the cost of significant quality of life.
Select Build Version
LoD Setup
Concept It is also possible to go for a Legacy of Dreams setup to benefit from all the supporting legendaries this build can benefit from. Since The Grin Reaper Mimics seems to benefit from Legacy of Dreams damage multiplier but not from Arachyr (6) Bonus, this build is an absolute beast when it comes to pure single target damage.
Gameplay In the Rift your job is mostly to survive and give the Big Bad Voodoo buff to your Trash Killer. During the boss fight try to dodge to keep Squirt's Necklace and make sure to keep Spirit Walk for your Physical Convention of Elements cycle.
Setups You can add in some additional toughness by changing the rune on Big Bad Voodoo to Ghost Trance. At higher Paragon, the Rift Guardian fight should be so short that you can take in Gruesome Feast passive and save some Health Globes before the Rift Guardian spawns.
Concept This build is a great Rift Guardian Killer. You add Bane of the Stricken and go for a full damage optimization. We replace Mask of Jeram and Depth Diggers by The Grin Reaper and Tasker and Theo to maximize our amount of Brood of Araneae stacks since we need single target damage.
Gameplay In the Rift your job is mostly to survive and give the Big Bad Voodoo buff to your Trash Killer. During the boss fight try to dodge to keep Squirt's Necklace and make sure to keep Spirit Walk for your PhysicalConvention of Elements cycle.
Setups You can add in some additional toughness by changing the rune on Big Bad Voodoo to Ghost Trance. At higher Paragon, the Rift Guardian fight should be so short that you can take in Gruesome Feast passive and save some Health Globes before the Rift Guardian spawns.
Drop Horrify for Big Bad Voodoo to increase damage.
Replace Piranhado with Wave of Mutilation to increase the range at which you apply the damage debuff.
Swap Molten Wildebeest's Gizzard for Bane of the Trapped since you have Pets and Spirit Walk to keep Squirt's Necklace.
Gameplay
Click Speed Pylon instantly to boost your mobility and dodge Green Meteors.
Around Wave 90, click Channeling Pylon and Power Pylon.
After Wave 100, use Conduit Pylon.
At Wave 122, stop attacking and run to the corner to let the timer run out.
We have awesome Echoing Fury, Big Bad Voodoo and Spirit Walk uptime as we are constantly killing enemies with Grave Injustice. Make sure you infest most enemies for the (2) Bonus spread damage which constitutes most of your AoE damage. To do so, you need to hit them with the Thread between you and your ArachyrSpider Queen. Making a quick circle around the pull while the Spider Queen is in the middle of it is a good way to infest most enemies in the blink of an eye. Remember that you can position her at will by throwing Corpse Spiders at that location. Use Spirit Walk wisely to damage burst with Shukrani's Triumph.
Video Guide
Mechanics
Spirit of Arachyr
(2) Bonus summons a permanent Spider Queen linked to you by an infested thread. Enemies hit by this thread are infested for 10 seconds. All damage done by Corpse Spiders to any infested enemy is also taken by every infested enemy. This bonus is at the core of the build, enabling the build to deal great AoE damage.
The Spider Queen is commanded to move where you cast Corpse Spiders, so be mindful about where you cast them.
(4) Bonus makes the Spider Queen leaving webs that last 15 seconds on the ground. These webs refresh the infest duration on enemies and grant you 75% damage reduction. The damage reduction effect lingers for 4 seconds when you leave the web.
(6) Bonus grants 11,500% increased damage to creature skills: Corpse Spiders, Plague of Toads, Firebats, Locust Swarm, Hex and Piranhas.
Corpse Spiders
Each Corpse Spiders cast throws a jar releasing 4 spiders that last 4 seconds and attack nearby enemies. Each Corpse Spider usually performs 4 attacks before despawning. Unfortunately, as is tradition for Pets in Diablo III, they have a tendency to stand still doing nothing or reposition themselves while attacking, which means you can expect slightly more than 3 attacks per spider on average.
Leaping Spiders can partially help circumvent the Pet targeting issue because they jump onto monsters up to 25 yards away but Widowmakers is preferred for its higher base damage.
The Spider Queen is useless because you can only cast one at a time and Brood of Araneae stacking damage multiplier cares about the number of hits performed.
Corpse Spiders is a primary skill, hence benefitting from Depth Diggers and Simplicity's Strength.
Corpse Spiders are considered Pets. This means they are affected by Mask of Jeram and Enforcer. Corpse Spiders Damage on your gear is a separate multiplier.
Attack Speed is not a separate damage multiplier nor an actual Attack Rate buff for Corpse Spiders. Attack Speed only increases the rate at which you can cast Corpse Spiders.
Tasker and Theo increase the Attack Rate of Corpse Spiders, allowing them to attack up to 6 times within their 4 second lifespan.
Brood of Araneae
Brood of Araneae grants a 100% separate damage multiplier to Corpse Spiders by default.
Brood of Araneae secondary effect applies a 1% stackable debuff separate damage multiplier to the target for every Corpse Spiders hit. Each stack has an independent 5 second duration. This is where things get interesting because it effectively means Attack Speed double dips! Indeed, Attack Speed allows you to cast more Corpse Spiders, meaning you get more hits while getting more stacks of this effect at the same time.
The theoretical maximum Brood of Araneae stacks can be calculated using this formula, with FPA being your Breakpoint, S the number of spiders per cast, H the number of hits per spider and D the stack duration. S, H and D are all constants with S = 4, H = 3 and D = 5.
For instance, with a 17 FPA Breakpoint on Corpse Spiders, you can get a theoretical maximum of 212 stacks:
This helps us to understand why Echoing Fury is that good for the build, since its 75% Attack Speed buff bumps us from 2.4 to 3.52 casts per second (25 to 17 FPA) meaning we cast Corpse Spiders ~47% faster and get ~47% more Brood of Araneae maximum possible stacks (144 to 212 stacks), resulting into a 1.47 * 1.47 = 2.16 damage multiplier.
Mask of Jeram
The 200% Pet Damage bonus from Mask of Jeram is a specific case: its damage buff is additive with your Elemental Damage (Fire / Physical / Poison / Cold). As a consequence, "Fire / Physical / Poison / Cold skills deal X% more damage" affixes (mainly found on Bracers and Amulet slots), grants a lower relative damage increase to builds using Mask of Jeram in comparison to other builds.
The Grin Reaper
The Grin Reaper spawns 2 Mimics that can cast most of your skills equipped. It used to be a popular item back in the days for zWD since their Piranhas casts for instance were stacking the damage debuff. However this got nerfed in Season 7.
The Grin Reaper Mimics can cast Corpse Spiders with your equipped rune. The interesting part is that these Corpse Spiders can proc the damage debuff from Brood of Araneae.
Tasker and Theo buff the Attack Rate of Mimics by 1.5 so they can cast more Corpse Spiders. At the same time, it also buff the Attack Rate of Corpse Spiders so they attack on average 6 times instead of 3-4.
This means the The Grin Reaper + Tasker and Theo combination brings you at the same time more Corpse Spiders and more attacks from them, which result in an insane amount of Brood of Araneae debuff stacks in single target since it creates an Attack Speed triple dipping.
Shukrani's Triumph
The 100% Damage bonus while in the Spirit Realm from Shukrani's Triumph is an additive damage buff, meaning its effect is additive with other buffs such as Pierce the Veil.
You are in the Spirit Realm when in Spirit Walk and when Spirit Vessel procs.
After the initial duration of Spirit Walk (2 seconds or 3 with Jaunt), you stay indefinitely under Spirit Walk until you attack 3 times or until you have any Elite enemy within 20 yards.
A very interesting property of Spirit Walk is that you do not generate aggro under this effect, which means you are invisible to all monsters. This mechanic can be used to your advantage on some Rift Guardians which need a target to perform some abilities (Bloodmaw's Jump for instance).
Locust Swarm
When applied, Locust Swarm jumps to another nearby enemy once every second. With Creeping Death, this effect stays permanently as long as you are in range. It fades when you move ~1.5 screens away.
The Cloud of Insects rune can be used to apply bleed to enemies for Pain Enhancer, as any Physical DoT effect provides the extra Attack Speed effect.
Piranhas Piranhado
This ability is one of the few ways in the game to pixelpull enemies.
If used on top of enemies, it pulls them close together but does not pixelpull most of them. In order to get the best pull possible, it has to be used on a spot with no other nearby enemies.
Gruesome Feast
Each stack, received upon picking up a Health Globe, has its own duration.
You need 5 globes every 15 seconds or one Health Globe every three seconds to keep it at full power.
The Intelligence bonus stacks additively with Soul Harvest's bonus.
In-Depth Season 27 LoD Corpse Spiders w/ Echoing Fury Build Overview
During Season 27, the LoD Corpse Spiders build was a force to be reckoned with as a RGK, able to destroy Rift Guardians within seconds (while creating massive lags in the process). The reason is that you could replace The Furnace in the cube with Echoing Fury and keep its buff fully stacked thanks to a zMonk using Sanctified Wave of Light. The resulting 75% Attack Speed buff is a tremendous damage buff for this build due to triple dipping.
Since The Grin Reaper Mimics seems to benefit from Legacy of Dreams damage multiplier but not from Arachyr (6) Bonus, this build is superior to its Arachyr counterpart in single target situations.
Gameplay In the Rift your job is mostly to survive and give the Big Bad Voodoo and Sanctified Horrify buffs to your Trash Killer. During the boss fight try to dodge to keep Squirt's Necklace and make sure to keep Spirit Walk for your Physical Convention of Elements cycle.
Setups You can add in some additional toughness by changing the rune on Big Bad Voodoo to Ghost Trance. It is also possible to give up some Attack Speed from Tal Rasha's Relentless Pursuit to take in Aquila Cuirass.
Summary
Put together the core items and acquire the full Spirit of Arachyr set.
Position your Spider Queen in the middle of packs and circle around your prey to infest them.
Stack Attack Speed and use those juicy Oculus Rings.