Eisla, Mutant Gaurdian

This creature enters the battlefield with 2 +1/+1 counters. Other mutant creatures all have an additional +1/+1 counter as long as Eisla is on the battlefield.
{u}{g}: When a mutant creature would leave the battlefield this turn, remove all +1/+1 counters from that creature, tap that creature, and they cannot untap until your next untap step.