Mana Burn

Monsters with the Mana Burn attribute remove mana in the equivalent of its minimum/maximum damage times 4 and deals it as additional damage. Monsters have twice the chance to hit and +20% magic resistance, they don't gain more resist if it would cause a third immunity or increase one of two immunities. Mana burn monsters can prove deadly to players with a high reliance on magic, especially if it is paired with Extra Strong for even more trouble; for all physical classes, having mana leech is useful to regain lost mana while fighting this type of unique.

Development
Due to a bug, melee attacks burnt 256 times more mana than intended, resulting in emptying mana virtually every hit.
 * This was because the engine subdivides each point of damage into 256 bits of damage for better rounding accuracy. The Mana Burn code applied this multiplication twice, so all Mana Burn Unique monsters dealt 256 times as much damage as they should.
 * The second "bug" that increased this damage to 512 times resulted from Hell difficulty applying a -100% penalty to all resistances. This includes the resistance to Mana damage, despite there being nothing that could raise that resistance in game. Thus, all attacks that drain mana drain twice as much in Hell.