Reincarnated as the Demon King's Son - Chapter 702 The Messenger

Oscar, a destitute young boy, died in a tragic accident and was reborn in the forgotten realm. As a member of the lowly Birch tribe, his solace comes from the fragments of a guardian's spirit, residing in his soul. After the decimation of his family in the hands of a powerful race known as the dreads, he embarked on the part of revenge, leading him to the path of transcendence.

He is an undead who is devoid of all humanity, he is the one and only supreme overlord, he is a man who has severe mysophobia.

There are many people who try to act cool in front of him, whatever soldier king, assassin, system user, transmigrator, reincarnator, the strong returning, the strong coming down from the mountain, person coming back from the immortal world, reincarnation of the devil king, immortal emperor possessing someone’s body, and so on, all of them do not know what will happen next

- Description from Novelupdates

The worst student of Westroad Academy. The disgrace of the Blake House. A new soul enters the body of Frey Blake, who couldn’t overcome his miserable life and chose death instead. “What’s with this body? I’ll have to work on tuning it from scratch.” The Great Mage Lucas Traumen, with the body of Frey Blake, gains a chance at revenge!

Set in a Pokéverse where the remnants of our civilization's Earth lie buried under the resurgent human/Pokémon societies, this epic Saga follows the protagonist through his journey to the heights of Pokemon Training and beyond, across a planet that was only saved from ecological disaster by an act of Arceus. As Humanity and Pokémon coexist in this fusion of settings, the story will explore themes of war, oppressive cults, and Shadow infusion, in a world where Pokémon healing and battles echo the anime in realistic, but not overtly graphic ways. Pokémon do not rip each other apart in Battles, though it can sometimes happen in the wild.This is a very long journey fic that's kind of a Crossover with everything. But with Pokémon. So you might see characters like Shaggy Rogers, or Izuku Midoriya, but with Pokémon teams. Pokémon legends like Red, Gary Oak, and the reigning World Champion, Ash Ketchum, are also, naturally, present in the setting. Think of this slice of the Pokéverse as one where it's all coming together.