He'll be playable, but he will be comped heavy to prevent an "only toy" list. I doubt a double Dread 13 list will be approved either. I'm leaning towards a negative on the taking of 2 13 spells at least.
I like the model. I feel he should only have 3 arms though!
Edit: So basically, I don't have a problem with multiple models in the list able to take the 13 spell, but on spell generation only 1 13th spell can be generated. Not trying to derail the thread with Brawl talk.