Seal of Denial

Flash
Seal of Denial enters the battlefield with two Casting Counters. As long as it has at least 1 Casting counter, you can't activate it's ability. At the beginning of your upkeep, remove one Casting Counter from Seal of Denial.
Sacrifice Seal of Denial: Counter target Spell.
"Some spells are not meant to be cast. Let me show you which" -A graduate of the Tolarian Academy