Blood Boil

Blood Boil was a spell in demo version of Diablo I. In the released game, it was cut.

General Information
Blood Boil would inflict 100% of the target's current Life in damage, but only in close combat (changed to ranged cast later). The mechanic was later reused for. In return, it would also drain the character's Life, as a percentage of the amount drained from the victim.

Damage Calculation:
 * Character Life Drain: (100% - (12,5% x Spell Level)) of the damage inflicted

Past spell level 8, it would actually heal the hero, even beyond maximum Life. Ironically, that would result in immediate game crash.

Presumably this spell would not work on Undead.

The icon was later reused in Hellfire for the Rage Skill.