Red Thirst

A side effect of the Black Rage is the Blood Angels' vampire-like tendencies. They generally have pale skin, and a strong urge to drink the blood of their enemies. This flaw is known as the Red Thirst. These traits have also been passed on to their successor chapters, such as the Flesh Tearers, Blood Drinkers, and Angels Sanguine.

One Successor Chapter, the Lamenters, managed, by unknown means, to eliminate the flaws from Sanguinius' gene-seed, but has been stricken by extraordinary bad luck in battle and as such has been nearly annihilated.