Faith!
Those golden angels, thoroughly awakened and teaming up to overpower an Abyss Lord's avatar, are consuming nothing but the power of faith, which is the kind of power that Divine beings can wield.
It's precisely because these powers are inherently so exalted that even an Abyss Lord must suffer defeat.
Of course, these angels are not Divine beings, but they are not far off either, because they possess part of the Divine's attributes at this moment, even if only temporarily, it's more than enough to suppress an Abyss Lord's avatar.
"This is the power of faith born from worldly angel worship, yet angels are not Divine beings, they don't have a divine status to convert faith into Divine Power, but it doesn't mean there is no way to utilize it... brilliant, truly brilliant!"
Having a master-level understanding of magic statues, Noah suddenly feels enlightened.
