Skill Gems
Purchase 2 Items that have 3 Green sockets for your weapon swap. Put sixx Seismic Trap in your Weapon Swap to Level while your progress your Atlas. Corrupt them to Level 21 once they hit Level 20. This is how your Gem setup should look like before entering Maps:
Early Game Gem Setup
IMPORTANT! You may not be able to cast Malevolence because of a lack of Energy Shield. Make sure Divine Blessing Support Stays at Level 1 to keep its cost low and wait until you obtain more ES gear.
Make sure to cast Despair and Temporal Chains on the boss alongside using Withering Step to apply a stack of 7 Wither debuffs (each stack increases Chaos Damage taken by 6%).
Early game uses Immortal Call and doesn't run Determination, but you can drop Summon Skitterbots and Arctic Armour to fit it and Molten Shell in if you feel too squishy against Physical Damage.
Mid Game Gem Setup
After obtaining a The Devouring Diadem, socket all Auras in your helmet, replace Arctic Armour with Determination and use Vaal Molten Shell instead of Immortal Call. You also need an Unset Ring to fit in a Defiance Banner.
Take note of the fact that there are TWO boot setups. This is because Exsanguinate is for mapping, and Blade Trap is for bossing so that you can apply 15 Wither stacks. You only need to swap to Blade Trap for Pinnacle bosses, not map bosses. One last note is to obtain a Level 21 Seismic Trap for an easy damage increase.
End Game Gem Setup
Purchase and use a Level 3 Empower Support to link in your Body Armour after you've obtained a Skin of the Lords. You need a Divergent Herald of Agony to drop some Poison Chance on the tree, and an Anomalous Molten Shell for an extra boost in your defence.