Mage Manual - Chapter 248 - 214 Sharing the Secret Poison

SSR-ranked killer Mu Hui died in an explosion, only waking up to find herself transmigrated into the body of a vicious female supporting character in a book.

Chu Nan was just an ordinary student, but because of an accident, he obtained the data collection, analysis and processing ability equivalent to the most advanced optical brain.

Gripes have their origins and debts have their creditors. We haven’t crossed each other in days past or present, nor formed any grudges. I am but duty-bound to carry this out, so apologies in advance!

In his past life, Yang Chen was a gentle person who was oppressed for his whole life.

Now that he’s reborn, he chose to become an executioner and severs ties and grudges with his executioner’s blade, killing all that climb onto the Immortal Executioner’s Platform!

Heads will roll! Humans’ in the human realm, demons’ in the demon realm, devils’ in the devil realm and immortals’ in the immortal realm!

- 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?