killem off, then over run

Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Whenever a -1/-1 counter is put on a creature, you may create a 1/1 green Elf Warrior creature token.

When this artifact enters, put a -1/-1 counter on each creature target player controls. , : Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)