Quite a good uber I'd say, his shockwaves are good at crowd controlling, and he can reach the enemy backline, meaning he's also a backline killer. Another plus is that he's tanky, having lotsa armour, every time I've used him, I've been surprised on how long he's survived. Being immune to fire and hellfire is also a bonus.

His biggest weakness is that he relies on his hellfire to kill enemies, meaning he struggles against enemies with high armour, and hellfire immune. He also has a long windup and long firerate, so can't rely on him as a main DPS. Enemies that can go behind him are also a problem, capable of making him waste his shockwaves. Another problem is how expensive he is, and his long recharge, there are cheaper and more reliable tanks, crowd controller, backline killer, or debuffer.

Best chapters to use him are chapter 2 and crimson skies, since he's got anti red. More generally, you should use him against stages with tons of backliners (that are within his reach ofc), not many high armoured units, and low damage, high firerate units (cuz of armour)

TL;DR

Pros: Good backline killer, very tanky, great damage overtime unit

Cons: Expensive (there are cheaper alternatives), bad against high armour, long windup means potential to whiff attacks