The Last Circle - Chapter 9: Titan

Witnessing her boyfriend cheating on her with her bestie, Shiyao was so angry that she went to a pub for fun and met a man, who was really a piece of work. After a crazy night she fled away, but was embarrassed to know that the man she slept with was her boss You Ze.
Jesus, give her a break!

- Description from Novelupdates

I can be the main character even though I’m not a hunter. Kang Moo-hyuk succeeded in all the raids with his genius and rose to the position of Strategic Team Leader despite not being a hunter.But one day, he got diagnosed with a terminal illness called “mana addiction”, and even got involved in a power struggle within the guild. With only a few days left to live, he decided to do everything he every wanted and set his passions ablaze. And he chose the tier 1 “Taesung Guild” to do so.But how can Kang Moo-hyuk grow the guild with Joo Se-ah when the rest of its members are amateurs?

The night before her wedding, her world shattered.Betrayed by her own sister and abandoned by her fiancé, who demanded her kidney as the price for his love, she thought her life was over. But she refused to be a victim.At the altar, she made a bold move: she called off the wedding and declared she’d marry anyone willing to step up. To everyone’s shock, he—the richest and most powerful man in the city—stepped forward, claiming it was his “duty” to marry her.Overnight, she went from a betrayed bride to the wife of her ex-fiancé’s uncle, turning the tables on everyone who wronged her. From navigating family drama to outsmarting scheming rivals, she rose to become the undisputed queen of both families, building an empire of her own.Now, with a thriving career and a husband who adores her, she’s living her best life. But when her husband calls, begging her to come home because their twins are “starving for attention,” she knows her chaotic yet glorious life is just getting started.

The maniac who was crazy about all kinds of fields such as military and steampunk had been reincarnated.

However, his father was King Sejong the Great?

The mania-wise king and his crazy maniac son.

Along with the ministers, and countless humans who were getting exploited.

Even today, the night of Joseon was filled with the light of overtime.