Generally speaking, you want to try and find cards that affect all of your opponents while leaving your own stuff untouched
It's reminiscent of Kiln Fiend creatures where each noncreature spell you cast pumps it for the turn, and it has a strikingly similar design to Livaan, Cultist of Tiamat
He can put counters on creatures to trigger things like card draw, he can gain us life to help trigger cards like Aerith, and he can return Summon creatures from the graveyard to play
A hugely overcosted wipe that you can't really game is
006-163-sail-the-azurite-sea and 005-157-tipo-growing-son easily take your inkwell from two to four, where a lot of the decks power resides
Duskana, the Rage Mother This is one of my favorite Commanders from MKM, and theres an obvious reason why