After being transported to another world through a video game, Seol died three months later along with his friends. After his death, he thought everything was over, but somehow he ended up being reborn as a Slime monster along with a powerful "Evolve" skill given by the system.

Photo Cover not mine, all credit to: https://www.pinterest.de/pin/392024342565050948/

Also, post on tapas and scribblehub.