MTL - Medical Princess - Chapter 1244 , Really found it!

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

Layland Kleinhaus (17) suffers from hypogonadism that makes him less “manly” on top of having a girly face. He is bullied because of it, but he always remains strong ... At least, until he can't bear the betrayals and sufferings anymore.

Filled with rage, indignation, and the lust for blood, he decided to end the life of his tormentors along with the bystanders before taking his own life.

Alas, in the middle of his deed, a mysterious being intervenes the act by summoning him and the rest of the bastards he is killing to another world. He curses his bad luck for not being able to fulfill his revenge because of it, but much to his surprise, there is something much better than having his revenge waiting for him.

“Layland... Be a Demon King.”

Thus, his journey of becoming the unparalleled Demon King begins.

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Those who know me are already in the know of my “condition”—minor dyslexia. So, if you find any misspell or 'wtf does this even mean' words, I hope you can pardon me from the insult, and notify me instead.

The strongest hero of humanity, Kim Sung Bin.