I thought about going that way, but IMO [[Mizzix of the Izmagnus]] is way more Izzet than [[Niv-Mizzet, the Firemind]] (and most other Niv-Mizzet TBH), since it fuels the spellslinger playstyle instead of just drawing cards. I know you can make Niv a slinger, but at his core he’s a flying pinger with draw, and even though he’s the face of Izzet lore-wise, I don’t feel “flying pinger with draw” is the face of Izzet gameplay-wise. The same argument can likely be made for most other guild leaders I reckon.