Jodah, Archmage Eternal In a 60 card world, Jodah is the sort of dork who can come down on turn four, and then ignite a fiery turn five with his alternate casting cost
Never has white gotten a better 1/1 creature with a targeted ability
Their shuffle and handling abilities make the process easier
Celes, Rune Knight Celes, Rune Knight is one of the most combo-centric Mardu commanders ever printed despite only being released in the recent Magic: The Gathering - Final Fantasy set
Shadow the Hedgehog seems like a frontrunner, in terms of power at least, due to how chaos control effectively makes any spell that you cast with a Treasure or mana rock uncounterable
That might not sound like it's a particularly good deal, but efficiency is efficiency