The Hero Reborn: Modera

For centuries, humanity has had many heroes who have sacrificed their lives to try and defeat the Demon Lord, but of course it wasn't an easy task. A being such as them only made it even more difficult for humans to try and fight against. Each hero that died would be reincarnated once again when defeated, it was a repeating cycle without them knowing what fate they have to experience, nor did any hero try to figure it out. The only mission they had in their mind: Defeat the Demon Lord. But are they the same person? Do they share the same soul? Could they be multiple people in one body? The answer remained unknown, until one day... A hero finally managed to defeat the Demon Lord with the cost of his life. Only managing to do so thanks to the skills he had learned as well as the passed down abilities he obtained through countless lives of the past heroes. He didn't know that of course. But what happens when a hero dies, without the existence of a Demon Lord to defeat? This is where the Legendary Hero who defeated the Demon Lord, River Thrin. Now reborn as Toki Keystone, must go through his new life in order to find out why he has been reincarnated into the future, or the modern era of magic society. Will he find out the truth, or will he live his life normally? Or, would he face the Demon Lord once again? [ Not sure if this is an isekai or maybe a reverse isekai, at all. But I wanted to try something a little different for fun, so I hope you guys enjoy reading it. ]