MTL - The Lady’s Sickly Husband - ~ 158 for the best treatment

[ Fusion Successful ][ Water Toad + Sky Dragonfly + Nightmare Moth + Bluefang Hyena= Nightmare Hydra ]----Yuki Igarashi, once a terminally ill boy confined to a hospital bed, dies with a silent wish for strength and freedom.That wish is mysteriously granted when he reincarnates into a fantastical new world. Not as a human, but as a newborn Frost Dragon.With his memories intact and curiosity alive, he is soon greeted by a mysterious system called the Dragon God System, which mistakenly binds itself to him, claiming he is not its original host. Still, it is now eternally bound to him.Despite his infant form and weak body, Yuki discovers he can extract bloodlines and skills from other creatures using the Dragon God Codex, and fuse them within a mysterious space called the Fusion Lab.Even more shocking, a glitch in the system allows him to repeatedly Fuse bloodlines without depleting them, opening the door to limitless growth.

The story follows Matt, a young man planning to delve the rifts responsible for the monsters that destroyed his city and killed his parents. His dreams are crushed when his Tier 1 Talent is rated as detrimental, and no guild or group will take him.Working at a nearby inn, he meets a mysterious and powerful couple. They give him a chance to join The Path of Ascension, an empire wide race to ascend the Tiers and become living legends.With their recommendation and a stolen skill, Matt begins his journey to the peak of power.

Aoki’s resolute face was indifferent. “If the sun doesn’t shine on me, please let me be surrounded by darkness!”
From a different perspective, look at the entire Pokemons world.

- Description from Uukanshu