You get the Collective Psyche set by farming the Desert Perpetual raid in Destiny 2; it’s raid-exclusive loot, so you’ll need repeated clears to finish the full set. The armor pieces come from specific encounters, with the helmet/chest tied to Iatros and the legs tied to Epoptes or Koregos.

How it drops

  • Iatros, Inward-turned : helmet and chest pieces.
  • Epoptes, Lord of Quanta : legs.
  • Koregos, the Worldline : legs.
  • The raid is non-linear, but you still need to complete the required encounters to reach the end.

Fastest way to farm

  1. Run the Desert Perpetual raid with a coordinated fireteam.
  1. Target the encounter that drops the slot you need.
  1. Repeat clears until RNG gives you the missing pieces.
  1. Use multiple characters if you want more weekly chances.

Quick note

The set is class-specific, so Titans, Hunters, and Warlocks each get their own version of Collective Psyche gear.

TL;DR

Farm Desert Perpetual , focus Iatros for helmet/chest and Epoptes/Koregos for legs, then keep repeating until the full set drops.