Lieutenant-Colonel Mikail Leonid

An Imperial Guard leftenant at first in the book Storm of Iron, in which he outlasted Imperial Fists and every other guardsman on the fucking planet, destroyed a fuckload of geneseed to stop Honsou gettinghis filthy heretic hands on it, and is actually not a Mary-Sue. Got captured by said Iron Hands, survived torture, got taken to and survived years in the Eye of Terror until Uriel Ventris came along and broke them out, destroyed a daemonic artifact, then had the balls to stay behind with two Greater Daemons of Khorne to buy Ventris time to escape.

Balls of Motherfucking Adamantium right here. Straken could learn something.