In a Commander game, the Piledrivers power will surely skyrocket to preposterous proportions, allowing you to (hopefully) swing at multiple players at a time for lethal damage so long as your board is chock full of those lovely, grubby little Gobbos
Vivi Ornitier's activated ability becomes even more potent when exiled by Agatha's Soul Cauldronan explosive synergy that the Izzet Cauldron decks are built to exploit
The design on Yennett is impeccable
Young Pyromancer is unique in the sense that I believe there are multiple types of decks that might want its services and the endless swarm of 1/1s the card is apt to supply
The snake druid has a CMC of 1G and can copy an activated or triggered ability from an Enchantment source, allowing you to choose a new target for the copy
If Ghastly Mimicry would be put into a graveyard from anywhere, exile it instead." The ability to create copies of your favourite creature is great, and even the standard clone effect is potent