Black Rage

From Warhammer 40k

The Blood Angels and their Successor Chapters still suffer from the psychic imprint left by Sanguinius's death (or by the "wound" caused on Signus Prime). This can cause them to go insane prior to or during battle and feel the rage of Sanguinius himself during the Battle of Terra. The condition is largely irrecoverable and only a few Blood Angels have managed to defeat the "Gene Curse". Victims are locked away in the "Tower of Amareo" (named after an ancient master of the Blood Angels) on the Blood Angels' homeworld. This insanity is known as the Black Rage.

Rather than let them face a slow, insane death, Blood Angels will form those who have newly succumbed to the Black Rage into a special unit known as the Death Company. They wear specially painted black armour, and are often led by the few Chapter officers, notably Chaplains, who are able to communicate orders to the insane troops. They are then sent out to perform the most dangerous assaults, hoping for a quick and honourable death in combat.