Gennick, Rekindled Wisdom

Flying, haste, prowess
Whenever an opponent casts a spell, counter that spell unless it's controller pays {x}, where X is the number of spells that player has cast this turn. If they do, you gain X life.
Whenever a spell or ability an opponent controlls is countered, return Gennick, Rekindled Wisdom from your graveyard to the battlefield.