Demon Master Boy

Men will remain young until the day they die. The passage connecting to other planes that was accidentally opened by someone allowed the demons to invade the earth, causing countless tragedies. The young love died tragically in front of him. At the end of his life, he ended this troubled world, but he could not save that person. Before he died, he lamented how great it would be if he could do it all over again. After experiencing thousands of reincarnations, I am back to my youth again. A butterfly flapped its wings, but the world became worse. One Piece, JOJO, and more planes invaded the earth. Facing a world that is collapsing day by day, what should a young man do? He will use the bitter consequences of thousands of reincarnations to save everything and reach the top in this world where monsters, monsters, and monsters are rampant.