Here's the situation, party consists of:
Marines Militant Tactical (Ultramarine variant)
Dark Angel Tactical
Screaming Gecko Librarian (frontal assault focused chapter)
Grey Phoenix Assault (Imperial Fist successor)
Wrath of Corax Assault (Ravenguard successor)
They are investigating some corrupted servitors when they are ambushed. A tough fight, ends in twelve rounds with the assault marines, librarian and Militant holding their own and taking down the corrupted servitors. The Dark Angel missed every single time. He had to be bailed out by the Militant and the Phoenix, who took down all their attackers and had to chop down the ones on the Dark Angel. The Dark Angel has demanded he do penance for failing so spectacularly (he had a 58% of hitting in melee after aiming). This was a bad run of luck, but in game he would be devastated at such a display of incompetence. I just can't think of how a Dark Angel would punish himself for this.