The Demon Realm was directly blasted by Eva and a chunk consisting of almost 1/7th of its total landmass was destroyed and turned into space dust. Hundreds of Demon Provinces were turned into ash, hundreds of trillions of demons turned into nothingness and easily killed.
Demon Kings were among this number too, including the 12 who came to confront them. It was so terrible that even the Will of the Demon Realm appeared and screamed in agony, as it had lost 1/7th of its landmass and power.
As for the Evil Trio, they received a huge surge of experience that couldn't be beaten away by their cruel classes. In this situation, they had killed so many beings that even with the exp being split into three, and with their classes each reducing that split exp to 0.001%, they were able to rush through many Levels.
The Evil Trio rejoiced as they felt themselves reaching their previous height of Rank 4!
