Dragon Tamer - Chapter 840 - 844 The Four Immortal Ghosts

A boy wakes up with omnitrix as a X-GENE

A great demon king who came from another world to conquer Earth. To save the Earth, Li Luyou could only first take care of this great demon king… a little girl proclaiming herself Her Imperial Princess.

- Description from Novelupdates

Summoning ceremonies can freely call forth even “those which lurk in the depths beyond the gods”. One boy has top-level abilities even among the cutting-edge summoners who can use those ceremonies. He is Alice (with) Rabbit aka Shiroyama Kyousuke. But this strongest boy summoner has a single fatal weakness. Certain “cursed words” spoken by girls: “Help me.”

When Kyousuke hears those words from Meinokawa Higan, a girl brought to the verge of death, he throws himself into a city where three great summoner forces clash!

At 79, Adom is an old mage who has known nothing but illness and regret. When the world finally burns and all hope turns to ash, at the last beat of his fading heart, a mysterious being appears in the dimming light with a simple question:“If you could try again, would you?”What's left to lose when you've already lost everything?A handshake seals the deal, and Adom wakes up on his old school grounds, sixty-seven years in the past. When everything is still possible. A second chance with all his knowledge intact, his memories preserved, and his youth restored.This time, Adom wants it all: to feast on food he's never had, to travel a world still full of wonder, to finally live the life he dreamed of. There's just, as always, one small catch—he needs to prevent the end of the world first.But as Adom will soon discover, changing history might demand sacrifices even greater than watching it burn...