Kill Harriet with poisonous gas.

After finishing the game once, kill all Visionaries in a map and escape.

Kill the Garbage Collector and acquire the Fugue slab.

Complete 'Ending It.'

Kill all Visionaries present in a map and escape without killing any Eternalists.

Complete one AEON dossier.

Complete 'Lost in Transmission.'

Complete 'The Ballad of Ramblin' Frank.'

Kill each Visionary at least once.

Kill Fia without causing a deadly reaction.

While playing as Colt, ignite a gas cloud while someone is inside it.

Absorb Residuum from a body - like some kind of temporal sponge.

While playing as Colt, kill Frank. Or Charlie. Or Fia. Or Wenjie. Or Aleksis. Or Harriet. Egor will do as well.