User blog comment:B214/General Discussion/@comment-82.178.100.57-20170709173414/@comment-10330822-20170717005359

Nothing really, that's all we know. Ddraig and Albion were Heavenly Dragons, and their strength was among Top 10. However, just because Apophis is also Heavenly Dragon-Class, doesn't mean he is also Top 10, it just means he's in the same class as dragons that were. Similar to how Rizevim is a Super Devil, but he's not strong enough to be in the Top 10 like Super Devils, Sirzechs and Ajuka.

As far as we know, Hades is still stronger, because he is the only one of the two confirmed to be among the Top 10.