There are many creatures with the ability Whenever this creature deals combat damage to a player, do X, nicknamed the saboteur ability
Whenever you cast a noncreature spell, Thor deals damage equal to that spells mana value to any target
Arcane Maelstrom Somehow Temur generals always present concepts I cant make practical sense of right away
While this may not sound all that impressive given that he basically comes with his own Invocation of Saint Traft attached, and the idea behind Voltron is that it's the Commander that deals damage, I found that this ability actually synergizes well with Mace of the Valiant, a recently printed equipment that gives larger bonuses when a creature enters the battlefield - something that will happen each time the Geist attacks
Scrappy Survivors is the perfect deck for just that, chock-full of Auras and Equipment to make your creatures tougher
The thing I really don't like about Morbid OpportunistMorbid Opportunist, though, is that it fails to do the most important thing for a creature deck: Help you recover or even punish a board wipe