Gravaton Mage

Energize 3, Protection from Gravity, Gravity, first strike
{e}{e}{e}{e}, place a gravity counter on Target creature
{2}{w/b}{w/b}{t} tap target creature with a gravity counter, until your next upkeep target creature loses flying and gets -X/-X until end of turn where X is the amount of gravity counters on target creature.
Graviton Mage gets +0/+1 for every 2 creatures with a gravity counter your opponents control