Aya Toma, Gunslinger

Whenever you cast an instant spell, put a shot
counter on Aya Toma.
{t}: Aya Toma deals 1 damage to target creature.
If there are six or more shot counters on her,
untap her and she deals 1 damage to herself.
At the beginning of each end step, if there are
six or more shot counters on Aya Toma, remove
them all and you gain that much life.