Sicarius, the Assassin

When Sicarius, the Assassin enters the battlefield, exile target creature.
Whenever you cast a spell, you may exile target creature with power less than Sicarius, the Assassin's power. If you do, put a +1/+1 counter on Sicarius.
When Sicarius, the Assassin dies, return all creatures to the battlefield under their owners control that were exiled with Sicarius.