X Mettaton, Sleet Siegebearer

Haste, Double Strike

When this creature deals lethal combat
damage to another permanent, it gains two +1/+1 counters and a Power counter on it

{ut} : X Mettaton, Sleet Siegebearer deals X damage to non planeswalker permanent
where X is the amount of Power counters on X Mettaton, Sleet Siegebearer