MTL - Boss Level Face-Slapping Specialist [Quick Transmigration] - Chapter 542 [1 more] Dressing as a substitute for marriage sickness (19)

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

After an unexpected death, a soul finds itself reincarnated into the body of Itsuka Shido, an ordinary teenager in a world filled with powerful spirits, magic, and dangers from other dimensions. With the help of a mysterious system integrated into his body, Shido gains the ability to travel across worlds, summon legendary anime characters, and unlock a wide array of random skills and abilities.Disclaimer: The cover isn't mine, credits to the original artist.

On the will left behind by the 14 year old suicide victim K:

“Taku Sugawara is the devil. Nobody should believe his words.”

[No fixed CP + wear books + brain hole cool text + women disguised as men + group pet]

Gu Lan crossed over and became the cannon fodder of the original book disguised as a man, counterattacked the protagonist of the original book who slapped her face, and lived in a dormitory full of sickly beauties.

Until one day, she discovered that her roommates were villains from other horror novels. After discovering the secret, Gu Lan thought she would be killed, but her roommates all looked at her strangely… Contrasted with cute Zhengtai, sickly and beautiful boy, split personality school girl, cold and stern school bully, romantic and noble son who plays Shura every day field.

- Description from novelbuddy