Blow it all down

Whenever another creature you control enters, put a +1/+1 counter on that creature and a +1/+1 counter on this creature.

Whenever a creature enters, that creature's controller may have it deal damage equal to its power to any target of their choice.

When this creature enters, it deals damage equal to its power to any target. Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)