I also think he’s way too convoluted and overloaded. I’m having way too much trouble trying to figure out how all the combos work, how to apply nether fyre and brand etc. Sure, you don’t want heroes to be simple and same-y, but there is a point where it becomes too much, and I think you’ve overstepped it here.
However, I do like how you’ve made Seyton a ranged, immobile mage, while Dismas is more of an enraged creature who chases down enemies. It’s fitting to a Mage and demon.
Also would you mind checking out my new hero design Saluman? I need some feedback on him, thanks.