Black Rage

All Blood Angels possess a genetic flaw which, when breaking a sweat in combat, sometimes causes them to go batshit crazy and forget about the Emprah for a bit and become lost in bloodlust. Other Space Marine chapters watch the Blood Angels in battle with a mixture of awe, fear and Codex induced jealousy.

Thankfully the Black Rage is not some kind of contagious space cooties, so other chapters are safe from it. It is certainly not related to Weaboo Rage when Astartes forces are on the receiving end of Tau weaponry.