Celes, Rune KnightCeles, Rune Knight is a recently printed commander that has great synergy with persist cards, as does Gev, Scaled ScorchGev, Scaled Scorch if you do a little work
This drastically speeds up the clock for opponents, especially if you have these in play simultaneously
He could even make a decent Commander, albeit one that limits you to a mono-white deck
For three mana you get a 3/2 with trample, and Mizzium Tanks ability is essentially Prowess with the addition of making it into an artifact creature
You are not trying to wait until turn six to combo off
Dimir requires plenty of mana to get things going, and this can provide an unblockable body to land encoded spells