You've Got Mail: A Cautionary Tale - Chapter 31 - Rumours

In the eyes of outsiders, Hyuga Yuuto is a genius in the traditional sense of the Hyuga family:

Tough, strong, gentle, and calm, he is a partner worth relying on at all times.

However, no one knows, in countless silent nights.

The young genius of the separation family stroked the caged bird engraved on his head and fell asleep with the sharp needle in his mouth, fearing that in his sleep he would reveal the madness and anger deep in his heart——

“What Uchiha Itachi can do, I, Hinata Yuuto, can’t dare to do?”

- Description from novelbuddy

[The Demon King is Dead], a story in which the Demon King got immediately killed in the Prologue. I became the ‘Demon Prince’ of said novel.

…Help me.

The Fake Life of a Villainess: Reincarnated as a villainous noblewoman, you become an experience bag for the protagonist on their journey. You are the target of the maid’s revenge, your half-sister takes away everything that belongs to you, and the grand princess who cared for you for many years finally loses hope and abandons you. The Real Life of a Villainess: You clean up the mess left behind by the protagonist when they disappear. And in their place, you teach her that as a maid, she shouldn’t always be thinking about…

What got summoned was the world’s strongest sociopath.