One use only. When an enemy spell has been cast, a Wizard with the Cube of Darkness can use it instead of attempting to dispel the spell using dispel dice. If he does so, roll a D6; on the roll of a 2+ the spell is automatically dispelled – otherwise the spell is resolved as normal. In either case, roll a separate D6 for every Remains in Play spell currently in effect; on a 2+ that spell automatically ends.