The Annulus

The Annulus enters play with 20 charge counters.
On your turn you may remove any number of
charge counters as follows:
1 - Target creature takes 1 damage.
1 - Detain target creature.
2 - Target creature is Unblockable this turn.
5 {dash} Target creature an opponent controls deals
damage equal to its Power to its controller;
triggered abilities do not trigger.