Bog Standard Isekai - Chapter 20Book 4.

Young Chen Xiang had a fateful encounter with a goddess & demoness and received their peerless heritage, divine pulses, ultimate martial arts, and transcendent alchemy techniques, which gave him an easy ride in his journey of cultivation.

When hungry, he refines some spirit pills to eat as snack, when lonely he flirts with the goddesses, when bored he teases those martial artists who came to beg for spirit pills, when tired he lets his beautiful wives massage him.

- Description from Novelupdates

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

This is a story of a man named Kim Sae-Jin, who one day, inexplicably wakes up as a Monster. Follow him and his perilous journey to get his life back as a Human, all the while growing even more versatile as a Monster in the process. This should be… complicated, somewhat.

[Nakseong High School, the heads of 300 people exploded!] Lee Joon, an ordinary high school student.During the entrance ceremony, he was caught up in a strange phenomenon and died.[You have died.] [Restarting from checkpoint.] [Loading…] And then a message appeared before his eyes.『Welcome to Nakseong High School that is full of mysteries and secrets.Uncover the dark secrets hidden around the school, or fight against urban legends and myths to earn points and unlock special abilities.Then, gather companions and stop the resurrection of the demon king before you graduate.The world is in your hands.』