This is really not mechanical ascension - Chapter 4 - 【Pneumatic Pressurization】and Tenglong Reagent

A surgeon accidentally got the blessings of a system, shocked the medical industry, and rejuvenated countless people.

- Description from Novelupdates

The girl submerged in the bottom of the lake suddenly opens her eyes. The noble ChuChao Gongzhu [Princess] becomes an abandoned daughter and woman. No problem. This type of slag father is not worth mentioning. By virtue of her exquisite medical skills, she becomes famous in the world. Slag father wants to reunite? Close the door, let out the dogs! Shizi [Heir of a noble title] wants to ask for marriage? Let him wait in line! The Regent has a chronic illness? Perfect. Godly doctor becomes a poison doctor. Let him neither live nor die and taste the pain of his evil deeds. She exacts bloody vengeance. Appointed Wuguo Gongzhu, she returns to her noble life. Slag father regrets, sister envies, stepmother hates!

This is a story of crime, scandal, and romance.

Baek Ain is your typical lazy guy.

He graduated from university at age 22 with a random degree he chose out of boredom and stayed single because fate decided so until that event happened.

“What? Where Am I??”

After a horrible incident, Ain transmigrated to another world. Or precisely to be a villainous and mobs character.

He died countless times because of the world's protagonists, gathering hatred toward them.

“What the fuck! What do you mean I stole your wife? I've been single since coming into this world!!”

“Hero, please save this world.” A goddess is begging me to save her world from the Demon Lord.

“Wait... Begone thot! That Demon King is my younger sister from 69th Transmigration.”

“How dare you!”

A beautiful heroine is hugging me from behind, wishing to accept her feelings.

“Shoo, Heroine! I don't need useless baggage with me. Side characters are better than you!”

And so, Ain's journey began to end this shitty transmigration cycle.