The Devil Who Learned to Love

Og'tharoz's counterattack was so powerful that it engulfed much of the battlefield. The black flames expelled through a central point in his right hand gained a very large volume very quickly, engulfing Belial in an instant.

One interesting thing about the higher demons is that each of them is created to be special in some spectrum of unique demon abilities, as examples for the lesser demons to follow, and that's why they are all so powerful.

So Og'tharoz and Belial, as two superior demons but from different generations, were not at all normal, they were unique.