You get two options and both of them are great: either an enormous army of vampires, or a 10,000 power/ 10,000 toughness dinosaur, with trample, that spawns in already attacking one of your opponents
We are mtg proxy producer
Or, for Mirth, what the toothed brain case is doing
I can see Jerren as a decent and interesting commander leading Mono Black Humans, but I think he's even more potent in the 99 of Human Aristocrat decks like Silvar, Devourer of the Free + Trynn, Champion of Freedom, and since so many of the best Clerics are Humans I think he makes a lot of sense in a Human-focused Cleric deck like Orah, Skyclave Hierophant
Youll be able to catch so many people off guard with this, and better yet, it doesnt even have to live
Lets do some quick math