Megumin

{t}, Exert Megumin: Put three magic counters on Megumin. Megumin deals X damage to each of up to X target creatures, where X is the amount of magic counters on Megumin. When you activate this ability for the first time each turn, put a +1/+1 counter on Megumin.
Tap another untapped creature you control: Untap Megumin.
"EXPLOSION!" - Megumin