A Dragonslayer's Peerless Regression - Chapter 164

Many strange phenomena have been happening in Yin City. Li Ang—whose alias is Li Risheng—becomes embroiled in an absolute real game of life-and-death, known as Killing Field.Using his above average analytical and deductive skills, he completes different quests assigned by the system, such as eliminating supernatural beings or solving cases, while trying to unravel the true nature of the game.

Collection of short stories.

- Description from Novelupdates

A 20-year-old genius medical student transmigrated to a book she read during an experiment and became a female supporting character named Mo Li.

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?