User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-77.182.213.61-20180706173845/@comment-10330822-20180707021356

It is mentioned the more he uses DxD, the more his soul and aura take on the appearance of a Dragon God. This means that if he uses DxD enough, he may become something of a Dragon God himself.

In EX, his dragonification form is strong enough to battle and kill gods, him using Boosted Gear was never even implied. He just mercs gods in base dragon mode. In that's the case, I'd have to imagine his actual base humanoid form is probably at least Satan-Class is not stronger.