Dark Heresy n' Friends
Literally the worst Psyker.
Varia was born in the Warp. Not on a ship in the Warp, literally on a planet in the Warp, one that only appeared in realspace once every few centuries. She was found by the Black Ships and taken to Terra for sanctioning, but honestly they should have left her there.
On Blakk-244, Varia daemonhosted, killing Kark and vanishing. She later reappeared on the Second Purpose, brought there by Nez Cafe for reasons unknown. Angered by being abandoned on Blakk-244, she caused a plague that killed eight thousand people on the ship, before being killed by Metalus.
She had such terrible luck. During the final battle, the very first time she manifested a power, she not only invoked Warp phenomenon, she DAEMONHOSTED.