Suterareta Tensei Kenja ~ Mamono no Mori de Saikyou no dai ma Teikoku o Tsukuriageru ~

So, get this – when the big sage died, he reincarnated into the future with some cool new magic he created. But get this, people thought he had no talent and ditched him in the monster-filled forest. Luckily, some goblins found him and raised him as their own. In return, he taught them magic and helped them level up. Now, he’s on a mission to build the ultimate monster empire. It’s the tale of the underdog kid who will rule as the monster king!