Moriar the Chosen
There are few harder in the Blood Angels or indeed any chapter than Moriar the Chosen. Once an honoured Brother-Captain of the Blood Angels Chapter named Morleo Moriar, he fell during the battle of Clamorga against the Eldar. Unable to repair the damage to his body, the Sanguinary Priest placed him into the chassis of a Furioso Dreadnought so he might continue to fight for the chapter. Along with a nearly unbeatable metal body came twin lightning claw dreadnought close combat weapons that would make Wolverine weep in bed in envy.
However, something that seemed to have not happened before to a Blood Angel in a dreadnought (really, what are the odds?) occurred and brother Moriar, on awakening inside his new life-support machine, was overcome by the dreaded Black Rage and the need for BLOOD! Yes, thus turned into a borg vampire and at the same time possessed with enough RAGE to make Khorne proud, brother Moriar became a walking avatar of death incarnate. Inducted into the Death Company as their sole dreadnought (at least before Matt Ward decided they needed more), this 'honour' has lead to brother Moriar the Chosen bringing many victories to the chapter. Of course, when you stop to think about it, since he is in a nearly invincible metal body it would be very difficult for the Blood Angels to put him down as they would with any death company marine that started to get out of control, so this honour along with the long periods of sleep they give him and the modified devices that allow him to sup his favorite crimson liquid might be the only things keeping him from running around Baal showing the Blood Angels what his lightning claw of death feels like....
On a fun note he is the poster boy/marine for Furioso Dreadnoughts everywhere and a perfect battering ram to lead the charge for your marines on the battlefield. We haven't heard much of his exploits yet but undoubtedly one of them was the removal of Failbaddon's arms with his pimped up claws during one of the pussy black crusades while the Blood Angels were chilling, drinking cocktails, playing 'hunt the chaos heretic', and generally owning the Black Legion.