Dreizehnn
Meh, evil will exist so long as sentient beings exist. Arguably even the gods have their own definition of evil. Though I wouldn't be surprised if his authority eventually evolves- chaos maybe? Darkness?
and speaking of beast, What's Roman's Nega Skill and noble phantasm? in this fic called dxd Annihilation Maker, he became a beast VI by becoming Lucifer and that one his noble phantasm Is to essentially circulate the seven headed dragon with the ten horns around earth itself to bring about the land of steel and thus also caused the arrival of types early ( probably, if he ever does it)