The huge dark lamp is featured in the corrupted chests Treasure Hunter promotion. Intially giving 10% more experience than the huge prismatic lamp, after unlocking the ability more loot per soul/chest: * 10 - Allows the Scrimshaw of aggression to be won and boosts the experience gained from a dark star/lamp to 20% * 40 - Allows the Scrimshaw of sacrifice to be won and boosts the experience gained from a dark star/lamp to 30% * 100 - Allows the Scrimshaw of corruption and Helm of corruption to be won and boosts the experience gained from a dark star/lamp to 40%