Fallen Empires

Merseine

Put three net counters on Merseine when it is brought into play. Target creature Merseine enchants does not untap as normal during its controller's untap phase as long as any net counters remain. As a fast effect, target creature's controller may pay creature's casting cost to remove a net counter.

Enchant creature
Merseine enters with three net counters on it.
Enchanted creature doesn't untap during its controller's untap step if Merseine has a net counter on it.
Pay enchanted creature's mana cost: Remove a net counter from Merseine. Only the controller of the enchanted creature may activate this ability.