We've been playing with the same group of characters since Dark Heresy was initially launched. During this time, our psyker has been keeping it relatively cool. There has never been anything truly serious in regards to psychic phenomenon. The most serious incident we've ever had was an arbitrator losing 8 points of toughness (having just bought his toughness to 40) due to excessive corruption points.
I've been kinda worried about it. The psyker player has been starting to calculate the actual odds of anything seriously bad happening... they are really very minor. I've felt the players started to lose respect for the perils of the warp.
That all changed today, during the closing stage of the House of Dust and Ash.
During the initial scene, Mourners charge into the attending guests from all sides... our psyker, a templar of the scholastia psykana, is a little frustrated that everything in his first barrage of lightning attacks miss, so on the next turn he decides to activate his precognitive strike, ignoring warnings that the veil feels oddly thin today. The dice come up 8, 8, 0. Three psychic phenomenon.Two are relatively minor, but the third leaves the psyker naked (save covered in gore), the rest of the group badly bruised, and every mourner within 7 meters burned to a crisp. Seeing how they were being overwhelmed by frentic fanatics, and someone had just requested a nuclear strike, the resulting Cataclysmic Blast wasn't entirely unwelcome - even if it did leave the group somewhat battered (and one arbitrator a few points into critical damage).
As a result of the damage suffered in this explosion, the now naked psyker is soon eaten alive by Shale crows as he cuts down poor Abbot Shale. The first fate point of the day is burned.
Everything is chaos, and the team is doing everything they can to avoid the really nasty surprises... like ashen tear assassins, slaugth and crazy head mourners. They catch on pretty quick, however, realizing that they need the unknown portrait to realize who the scion of Haarlock might be. Returning to the Garden of Lost Saints, the psyker tries to sneak past the erratic gun servitors that have recently reactivated. The resulting disruption of gravity has everyone in the vicinity Falling Upwards, and then down, seven meters leaving the psyker (who was at 5 critical damage at the time) to burn his second fate point of the night.
At the dramatic climax of the Haarlock Deathtrap, the players are crouching around the Gilded Widow - one arbitrator suffering from blood loss, and no one having any medicae skill. The psyker decides to try to heal his comrade to staunch the bloodflow. Another peril of the warp result sees the psyker's healing power turned on himself, taking 15 damage from the warpfire backlash and burning to a crisp. The player decided that the dice really didn't want him to survive the night. The Gilded Widow's prophecy proved true - his fate was flames and ashes. RIP.
Oh yeah, and the dying arbitrator ended up needing to burn a fate point once any hope of psychic healing was beyond reach.
In the end, two arbitrators, both badly into critical damage, one hanging on to life through sheer force of will alone, managed to drag themselves out through the front gates of the House of Dust and Ash as the building erupted with volcanic fire behind them.
"Only in death does duty end."