I Am in Marvel with Unlimited Cards - Chapter 31: IMUC- - COOPERATION

In the final year of high school, Christian’s ordinary life takes a dramatic turn when he is struck by lightning, awakening the Idle System, a manifestation of his dream.What begins as a personal fantasy quickly transforms into a new reality for Christian, who revels in his newfound abilities while the world around him remains blissfully unaware.However, as Christian adjusts to his extraordinary circumstances, strange and unsettling events begin to unfold globally.Would the genre of the world also become Fantasy or would it stay exclusive to him?

As a kind of punishment, the wings of a demon king were cut, and he eventually lost all of his power. To get back his power, he made a deal with the angel. He will go to the realm of humans to find a special girl with a special skill who is meant to be her queen. If the woman got pregnant, all of his sins would be forgiven, and he will regain all his powers. But he didn’t think that knowing her would be an adventure for him as the king of demons in the human realm.

A tale about the former leader of a special organization served under royalty, now leaving his past life behind and unintentionally getting involved with the martial world.

- Description from Novelupdates

Haewon, a violinist, is a nonchalant person who neither blocks the ones who come into his life nor holds onto those who leave. One day, his only friend, Taeshin, commits su*cide, and after failing to speak to Taeshin, who called him several times shortly before his death, Haewon is haunted by his death, even though he doesn’t have much of an attachment to human relationships. Then, he inevitably runs into Woojin, the man Taeshin had a crush on, and Haewon indifferently crumples up the business card Woojin hands him.One day, Haewon, forced into an unwanted relationship, becomes entangled in an assault case, but thanks to the business card given to him, he receives help from Woojin, who’s a prosecutor. Haewon feels uncomfortably guilty and tries to keep him at arm’s length, but Woojin is comfortable enough to take a few extra steps.