Citadel for All: The Only Unit Angel at the Start of the Game - Chapter 10: Killing an Elite Boss!

A little ruffian who fought recklessly without any morals and bottomline accidentally time-traveled to parallel space and became a Key Case Investigation Team agent. The huge change in identity had him creating chaos in the police station. However, a strange miracle system helped him repeatedly solve mysterious cases, turning him into an impudent ruffian detective!

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.

Gu Nianzhi had no idea how to get the aloof and handsome Major General to fall in love with her.

His eyes were dark and serious. “…Seduce me. If you can do it, I’m yours.”

Gu Nianzhi: “!!!”

- Description from Novelupdates

Being sucked into a fantasy world that nobody leaves doesn't sound half bad to Cain. He was a high school dropout with a drinking problem, living off disability due to his poor health, so it's not like he had much to lose except a few faithful friends he didn't talk to enough.

After a long night of drinking, Cain wakes up looking at what he believes to be the character creation screen of one of his beloved virtual reality games, but with no recollection of having purchased it. His unwitting choice to use the Random Character Creation option, unaware that the choice would be irreversible, sends him into this new world as a Puppet Master, a Summoning based class nobody else in the starting zone has ever heard of.

But as he soon realizes, this is no game, him and hundreds of others have been brought to another world with no instructions, no clear goals and no way home. It's a second chance to live a good life, but what will Cain be able to make of it?