Once, I wanted to be a good person - Chapter 11: The Scene of a Large-Scale Werewolf Game

The strongest Hero in history, Nakamoto Keisuke.

He was summoned to another world in the spring at the age of fifteen years old, and when he successfully defeated The Demon King, he was already thirty-two years old. He had finished his role in another world and returned to Japan, but the reality that had been waiting for him was, “Middle school graduate with seventeen years of blank period” label. He couldn’t find a decent job and had no choice but to spend his days working part-time.

Before such a Nakamoto, a beautiful girl who self-proclaimed had come to return the favor, appeared. “I’m the reward for Hero who had defeated Demon King”, said Angelica, a girl who came from another world that persistently tempted Nakamoto to make her his wife. Together with a high school girl who looks like Elsa, his beloved girl that he lost in another world, Nakamoto with his cheats skills got caught in a harem life.

Imagine a system that would let you create any skill you could imagine. Being the best at whatever you dreamt of becoming.Felix, who thought his whole life would remain average and ordinary despite hating it gets an unescapable chance to encounter the Legendary Truck-kun. Knowing it was a chance to change his life, which was a repeat of struggle every day, he happily accepted his ticket to Isekai.Waking up in the body of a wounded boy in a fantasy world, the boy finds out that his fate seems miserable. After nearly experiencing something worse than death, he finally awakens the Great Skill Creation System.Creating skill after skill that lets him achieve his goal, Felix treads upon the darkest of secrets and conquers a myriad of worlds with his trustful comrades. Watch how he changes the fates of everyone and the universe on his mystical journey.

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

A back-to-basics(?) monster evolution novel.