Skraket

"'WHAT the FUCK???! How DARE YOU INSULT MY GRAND MOTHER?'"

Skraket is a Dark Eldar of the Kabal of the Black Heart. He wears a hell mask.

TTS Canon
Skraket is first seen on the transport ship carrying Xylatro, Jebarion, and Leman Russ to the Crucibael Arena. When Russ grows bored on the trip, Skraket suggests playing 'Mon-keigh baby amusement game number 3' to keep him distracted. He invites Russ to play and explains the rules. Since Russ is implied to be a latent psyker, any word he thinks of manifests in reality. In the second round, Russ summons Urist, who berates and threatens the Drukhari. Skraket meets his end when Urist tackles him off the ship.

Trivia

 * Skraket bears many similarities to Hevestuli from Episode 26 part 2. It's unknown if they are the same character.