Quohm, Beholder

Quohm, Beholder enters the battlefield with
X Eye counters.
{t}, Remove an Eye counter from Quahm,
Beholder: Counter target spell and each spell
cast until the end of your next turn unless its
controller pays an additional X, where is the
number of Eye counters on Quohm, Beholder.
Target opponent gains control of Quohm,
Beholder.