Overclocked Electromancer (M3C-058) - Modern Horizons 3 Commander: (Extended Art) [Rare]

At the beginning of combat on your turn, you may pay . If you do, put a +1/+1 counter on Overclocked Electromancer.
Whenever Overclocked Electromancer attacks, double its power until end of turn.
Whenever Overclocked Electromancer deals combat damage to a creature, if that creature was dealt excess damage this turn, you get X , where X is that excess damage.