Demon King & Hero - Chapter 9-1:

A teen is summoned to another world as the Hero. It turns out the Hero can power up women with his cum.

Ariadna Lereg Ilestri Pre Agrigent. And so my life begins with this ridiculously long name, born to royalty and the center of attention — all because of one dangerous man; the veritably insane tyrant king, ruthless conqueror of ten empires, nightmare of all continents… and my father?! Will I be able to survive this maniac?

I don’t know the length of Hydra, or the depth of S.H.I.E.L.D.

I don’t know that Ant-Man has an outfit, and I don’t know that the Winter Soldier has an iron fist.

I don’t know that there is chaos in the Bliss Space, and I don’t know that Miss Xiaoyu wants to get married.

I don’t know if the walking corpse is cheating, I don’t know whose fault the alien is.

I don’t know the legend of mutants, I don’t know that Kryptonians can’t afford to provoke them.

I don’t know that Black Panther’s family has a mine, and I don’t know that Iron Man is a mess.

I don’t know what happened to Lei Shen’s family, and I don’t know that Thanos is thinking about making troubles.

He doesn’t know the past or the way forward, he only knows that he stands firm at the critical moment and cannot be cowardly.

- Description from novelbuddy

The protagonist transmigrates into a novel and gains a system where they grow stronger by simply writing in a diary.July 7th, sunny: “The boss’s outfit is hideous again. Wouldn’t it be better to wear something cooler?”July 7th, evening: “I’m about to have my engagement called off. So excited! How should I act?”July 7th, evening: “Lin Qingyue, the female lead, is probably going to drown her sorrows in alcohol.”The protagonist thought it would be easy—just jot down daily musings, record life’s events, and earn rewards. All while playing the part of a villainous, bootlicking second-generation rich kid, moving along with the original plot.But unexpectedly, the female leads gain access to copies of the diary entries.One by one, they stop following the script, and the plot spirals completely out of control.July 10th: “The female boss is an idiot—no one would want her.”Soon after, the protagonist gets punished at work, all because they entered the office with their left foot first.