I Studied Abroad in the Modern Times - Chapter 115Book 2: : Practiced Wrong

This is a world filled with despair, teeming with hordes of corpses, mutated creatures, poisonous plants, demons, and gods.The human societal system has completely transformed, with no justice, no righteousness, only might and slaughter.The strong can oppress the weak at will, human order has utterly collapsed, and the law of the jungle reigns supreme. In this world, weakness is the original sin!Some lucky humans have awakened extraordinary abilities, becoming Evolvers, and have risen to the top, possessing wealth, resources, beautiful women, and status.Qin Jun crosses into this doomsday world, awakening the Great Villain System at the start. As long as you are villainous enough, SSS-level talents, gene serums, and potential points are all within reach.Perhaps in the doomsday world, only villains can climb step by step to the peak…

An ordinary (?) grandfather, Choi Chuntaek. In an effort to protect his granddaughter, he started the virtual reality game 'Arkstar.'

Then... he accidentally obtained a legendary class?

The worst student of Westroad Academy. The disgrace of the Blake House. A new soul enters the body of Frey Blake, who couldn’t overcome his miserable life and chose death instead.

Xia Yan passed through to the world of Bleach and became an eleven-year-old boy. He was rescued by Renji and Rukia in the Seireitei, and he was studying at Shin’ō Academy, and he was a student of the same class.
He is a top student of the Shin’ō Academy, and he is vying for strength by various teams. In the end, he has entered the first team of secret mobile maneuvers.
He will use punishment to kill every person who tries to threaten the martyrdom and protect his loved one.

- Description from Novelupdates