User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-82.160.23.173-20180626165811/@comment-10330822-20180710073717

Dragon God seems to only imply stronger than Heavenly Dragon, which even after her nerf is what Ophis is. Problem is Lilith might actually not be that strong, but its probably her status as a piece of Ophis that makes her a Dragon God, not her actual strength.

The implication of Balberith being Dragon God-class seems to be that he is more powerful then something like Apophis, Crom Cruach, or Azi Dehaka. In short, if Issei fought him he'd be one of the most powerful enemies Issei has fought.