MTL - My Extraordinary Achievement - Chapter 97 There is really mine in the house.

Adam, who mysteriously transmigrated to the Marvel universe over a decade ago, has established the powerful Umbrella Corporation. Now, he's unleashing a new era of viral evolution. The Progenitor Virus, T-Virus, C-Virus, and G-Virus are just the beginning of his sinister plans.As heroes and villains struggle to contain the chaos, new threats emerge: the Blacklight Virus, Z-Virus, and the dreaded Cthulhu Virus. Adam's shadowy influence grows, pushing the Marvel universe to its limits.

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.

1. Download a suspicious game
2. Catch a few magical pets as partners
3. Go through interesting daily routines and lead the pet shop to a whole new level

- Description from Novelupdates

A fighting genius.