Lagon Chapter 8 Boss Guide

Lagon is a three phase fight that gets progressively more difficult. He also boasts a guaranteed one shot mechanic and several others that one shots most builds. Players need to understand how to properly position in order to defeat this Boss.

In this guide we cover Boss mechanics, and provide a strategy for defeating this Boss.

This is the campaign version of Lagon. For the Monolith of Fate Timeline, check out our Lagon - Ending the Storm Boss Guide. Want a comprehensive guide for the campaign? Check out our Campaign Walkthrough.

Starting the Fight

To reach Lagon you need to head to the Seafloor Coliseum. To get there:

  • Follow the main quest through the Moonlit Shrine and the Temple of Lagon.
  • Before you can enter the Coliseum you need to fight Architect Liath who guards the entrance.
  • Once in the Coliseum head up the stairs on the right or left side and Lagon will emerge from the water, starting the fight.
The green circle is where Lagon is.

Boss Mechanics

Lagon is the most mechanically intensive fight up to this point in the campaign and the jump in difficulty catches many players by surprise. This level of intensity is the new norm for Bosses from this point onward, so understanding how each fight works dramatically improves your chances for success. Below we have listed all of the skills that Lagon has available to him throughout the fight, along with descriptions and videos showcasing the skill. The following section has a detailed strategy for defeating Lagon. Learning the skills and strategies ensures your success against Lagon.

Moon Beam

Lagon rises up and then moves to either side of where the player was standing when he started. He then sweeps towards and across the player's original position with a beam that deals extremely high Cold and Lightning Damage at a high rate of fire and Chills. This attack one shots almost every build!

Moon Shot

Lagon lowers his head and then fires a quick beam in front of him, dealing moderate Cold and Lightning Damage. He only uses this skill when below 65% HP.

Moon Blast

Lagon rises up and places a large circle on the ground below him. After a short period he blasts the area with very high Cold and Lightning Damage and Slows. This attack one shots many builds!

Lightning Strikes

Lightning strikes random areas of the arena throughout the fight, dealing low Lightning Damage. A circular telegraph appears on the ground moments before the attack occurs.

Melee Attacks

Lagon strikes the ground in front of him with either his left or right claw, dealing moderate Physical Damage. His left claw (on your right side) is a guaranteed 2 second stun on hit.


During phase 2, Lagon's tentacles appear in the arena. They deal low damage Physical Attacks but have a high Stun Chance. You must kill these in order to progress to Phase 3.


During Phase 2 Flayer Sharks and Crabs spawn throughout the phase. Neither are a major threat but the Flayer Sharks can get dangerous if too many are allowed to accumulate.

Cold Waves

Starting at Phase 2, these waves do a moderate amount of Cold Damage and serve as a gear check for the fight. Builds with low Cold Resistance struggle to overcome these. They can be dodged but their spawn rate is so high avoiding them all is difficult.

Lagon Boss Strategy

Lagon is a three phase fight. In Phases 1 and 3 you deal directly with Lagon. In Phase 2 you fight adds while killing Lagon's tentacles. The fight is largely Cold and Lightning Damage, but also includes some Physical Damage so be sure to cap all three Resistances. There are several one shot mechanics in this fight, including one of the most punishing Boss mechanics in the game, so knowing how to deal with these mechanics is vital to defeating this Boss.

Phase 1

You start in the middle of the arena and need to run up the stairs on the left or right side to engage the Boss. In the first phase Lagon has most of his abilities, including the most dangerous ones so you'll need to be on your toes from the start. Here are some general strategies:

  • Stand in the center of the platform. It makes a huge difference when trying to avoid Moon Beam.
  • Whatever you do, don't get hit by Moon Beam! This attack sweeps across a large portion of the arena and one shot almost anything. Lagon starts the attack by rising up and then repositions to either side of the player. The best way to avoid this attack is to stand and wait for Lagon to reposition himself (he will NOT start the attack on top of you if you stand in place), then move to the opposite side of the platform. Make sure you're near the middle of the platform when he starts the attack or you might not have enough room.
  • Do not get hit by Moon Blast. It's a well telegraphed attack with a big circle AoE so you shouldn't miss it.
  • Avoid his Melee Attacks, especially the left one (your right). It always stuns and could mess up your timing with more dangerous attacks.

Phase 2

Once Lagon reaches 50% HP he teleports you to the center of the arena. This phase has entirely different mechanics from Phase 1:

  • Lagon's Tentacles spawn throughout the arena that deal low Physical Damage and high Stun Chance. They must be killed in order to progress to the next phase. The moon in the center of the ring fills up as you kill more Tentacles and once it's full you are teleported back to Lagon where Phase 3 starts.
  • Flayer Sharks and Crabs continuously spawn. These aren't immediately dangerous, but not dealing with the Flayer Sharks causes them to accumulate and potentially overwhelm you.
  • Cold Waves sweep from one side of the arena to the other. They do moderate Cold Damage and there are so many of them that it becomes difficult to avoid them all. Getting stunned from a Tentacle only makes avoiding these harder. Make sure you have capped Cold Resistance in case you need to tank a few.

Phase 3

After killing enough tentacles you are teleported back to Lagon. This phase is identical to phase 1 except Lagon is quite a bit tankier. Continue to follow the mechanics just like you did in phase 1 and you'll take down Lagon!


  • Lagon is a three phase fight with two phases involving Lagon and one add phase.
  • He has some of the most punishing mechanics in the game.
  • Cap Lightning, Cold and Physical Resistances.
  • You need to kill the Tentacles to progress from Phase 2 to 3.
  • Whatever you do, don't get hit by Moon Beam!



Written by McFluffin.
Reviewed by Facefoot, Lizard_IRL, Raxxanterax.


Feb 5th 2023
Article created