A Mastermind? No, I'm just the Live-In Son-in-Law - Chapter 20: The Prince’s Secret

He was very happy to be reborn, but why was he sixteen again, he can’t bear to look back at that time.

Why does he return to being sixteen years old, yet still meet Doomsday?

It’s alright to encounter the end of the world, so why did he have to fall in love with someone?

Even if he falls in love with another person, why did it have to be a man?

Falling in love with a man is also alright, so why did it need to be a secret one-sided love?

Even a secret and unrequited love is alright, so why is that man his….

- Description from Novelupdates

Seventeen-year-old Grayson has endured a harrowing childhood, leaving him with a dark and twisted philosophy. Driven by this painful doctrine, he imposes his skewed beliefs on everyone and everything around him. His malevolent actions draw the attention of an ancient evil, an entity wrapped in darkness and legend. This being sees in Grayson the potential to carry on its legacy.As the ancient evil begins to mold Grayson for a future drenched in darkness, he finds himself drawn deeper into a web of manipulation and control. Questioning whether he has the strength to defy the fate that has been thrust upon him.Theós, an ancient deity whose origins are lost to time, rules with an iron grip, instilling fear and absolute control over those who dare challenge him.“If it is not within Theós' plan, it cannot be done!”

The NPC sets out on a journey to defeat the Demon Lord, joined by beautiful girls he meets along the way.---This is an NSFW story, so if you're under 18, turn back now, son. No NTR, and no full-on Yuri. There might be slight Yuri—like girls kissing and stuff during threesomes—but it's not that kind of Yuri where the girls fall in love with each other while in a relationship with the MC.---