This page of the guide to Psychonauts 2 contains a description of the boss fight - Die-Brarian.
You’ll encounter this enemy in Cassie’s Collection.
Stage 1
The fight against the Die-Brarian is very simple and predictable.
You’ll spend most of your time fighting regular enemies, only hitting the boss once in a while.
it’s crucial that you destroy small enemies which prevent you from targetting the boss.
Once the boss falls, summon an Archetype by using Projection.
Let him into the boss' mouth to start the second phase.
Stage 2
This phase doesn’t differ from the previous one.
Once again, get rid of regular enemies, then attack the boss.
you’ve got the option to throw things at it, shoot it or attack it with fire.
Stage 3
This is the final stretch.
Empty the boss' health bar to finish the battle once and for all.
Defeating the Die-Brarian completes this chapter of the game.
