Lumer, a planet with a mysterious name, is a battlefield for countless monsters and powerful beings. This place, where endless battles rage on and the boundaries of the land seem to stretch into eternity, can truly be described as hell. And I was just a mere human who had fallen into this hell. Among beings who could easily crush human bones and more, humans were nothing more than pitiful and feeble creatures. I, Lee Seojun, was such a human. “Fusion.” I was nothing more than a human, but as an experiment, I possessed a unique ability. An ability to attach myself to another body, assimilate with it, and use a new body as my own. “I survived.” With that ability, I had to attach myself to the bodies of monsters and become one of them in order to survive. And finally, I defeated a being that could be called the King of these monsters on the planet Lumer. Having survived, I took what the guy had. [The system recognizes a new owner for the final boss, Aion.] [The player returns to their original world.] Now, I could go after them.