Ventaurian

Manafuse {r}{r}{g}{g} (You may cast this spell for its Manafuse cost. If you do, it becomes green and red
and loses all other colors.)
Whenever you cast a spell that shares a color with Ventaurian, gain 1 life.
Whenever a player activates an ability that isn't a mana ability, if Ventaurian is red, it deals 1 damage to that player.