Regressor Instruction Manual is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here.
The Summary is
One day, I was summoned to this world.
Beasts poured out, and an incredible crisis came.
My talents couldn’t have been worse.
[The player’s talent level is at rock bottom.] [Almost all the numbers are hopeless.]
Whether you have to become a warrior or a wizard.
Whether you’ve gone back in time.
You have to take advantage of everything in order to survive.
“What about it?”
“I’ll use everything I have to survive!”
An award-winning novel (2019).