Dominique

"'Hey Fyodor, I think we're in the Warp. Make sure you clench your butthole so no heresy gets in!'"Dominique was a lexmechanic attached to Fyodor Karamazov's throne of judgement.

TTS Canon
Dominique spent most of his time acting like a loon, making a mockery of whatever situation he and Fyodor find themselves in. He'd also try to take credit for whatever Karamazov says. Karamazov, annoyed by his antics, would frequently tell him to be quiet. He was addicted to sandpaper cigarettes, which he claimed was what gave him his "sexy" voice.

Dominique eventually perished in the warp from daemon-alcohol overdose. However, his spirit returned for one final appearance as he guided the Star Child and Saint Celestine to Karamazov, who later thanked him for preparing Karamazov to serve as the Star Child’s vessel, suggesting that at least some of Dominique's antics were purposeful. Dominique bade Karamazov a happy new year before disappearing. After Karamazov's transformation into the Star-Fyodperor, Dominique's rotting corpse was interred into a shiny new coffin beside him.

Quotes

 * "Hey Fyodor, look. it's that giant walking banana that tells me to burn houses down and kill things!"
 * "Wow, this man is so deep I could drown in him."
 * "Hey Fyodor, you should just preach them to death."
 * "I'm sexually confused, Fyodor! Kill them all, Kill them all! Quick, left-shoulder man, shoot them while they're still sexy!"
 * "Hey Fyodor, we're surrounded again! And this time by loads of half-naked men! It's like a ruddy ocean of bare nipples and bulging muscles. It's making me moist."
 * "HOLY SHIT, IT'S A CAT-MAN!"
 * "Hey! Hey Fyodor! Have a happy new year, pal..."

Trivia

 * Being a lexmechanic, Dominique was technically a member of the Adeptus Mechanicus, though he is not identified as such in the story.