MTL - Start with Batman - Chapter 331 Come whenever you want?

Betrayed. Exiled. Murdered. Reborn.In the war-torn land of Glory, power is everything and Duke Merlin's bastard son has none. Cast out to a starving border town beside the cursed Devil Forest, Kaelor and his mother were meant to die quietly.But when assassins take her life and leave him bleeding in the mud, another soul awakens within him one from another world.And with it, something else awakens too...The Fusion System.A power that lets him fuse nearly anything.Fusing one starving soldier with a dead direwolf gave birth to a Dreadwolf Trooper.Fusing one hundred wild dogs produced the monstrous Cerberus.Fusing two crumbling forts created a living fortress bristling with autonomous ballistas.From broken men and dead beasts, Kael will forge an army the world cannot understand and a dominion no one will dare challenge.

Synopsis below:How did the Avatar universe change when a transmigrant appeared in an unknown village, long before the canonical events? And how are the two islands Kyoshi Island and Uzushiogakure no Sato (A village hidden in the maelstrom)?---Tags: AU, Before-canon, Post-canon, Violence, Death of major characters, Transmigration, Harem, Children, Incest, Romantic. Foul language.

A boy awakens alone in the Fairy Tail world, lost and uncertain. As he ventures through this magical realm, he unravels the secrets of his mysterious new identity, unlocks hidden powers, and carves out his destiny in a land brimming with wonder, danger, and limitless adventure.“Check out my other work, Reincarnated as Ash: A Pokémon Tale.”

A minus’ hand that fails every singer he put his hands on, Kang Yoon.