Library of Heaven's Path 2: Eternal Fate of the Heavens - Chapter 6 - Moyun Jade Stone [Thanks to the Sword Quintessence Alliance Head]

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

Arthur Grail, a hardcore player of the VRMMO Trinity Star Online, woke up one day in the body of Gerard Astoria—a petty villain fated to die before the main story even began. To make matters worse, Gerard's death was a crucial event in the game's narrative. If he didn’t meet his predetermined end, it could disrupt the story entirely, leading the universe toward one of the countless “bad end” routes!Unwilling to leave his fate to chance, Arthur decided to take matters into his own hands—recruiting the “player” as his partner to help him clear the game and rewrite his destiny.But wait—“Why is the player not a dude but a sharp-tongued beauty instead?!”Follow Arthur's odyssey, filled with trouble at every turn, as he works to uncover the mystery behind his awakening in a universe eerily similar to Trinity Star Online's setting, all while trying to save the entire universe… without forgetting to enjoy himself!

Qin Guan was reborn and sent back to his final semester in High School 18 years ago. Getting a second chance at life, he works hard to turn things around and eventually become a Prince Charming. What will his life be like the second time around? What will he have to go through? How will he succeed in turning from a loser into a Prince Charming?

This story is about a rookie researcher, who was forcefully dragged away from his restful life, compelled into facing various killers and zombies, always having to risk his life at the brink of death, and finally becoming an advanced researcher that is acclaimed by all. And throughout his adventure, he met an alluring(?) killing machine, who he started to have fantasies on after they had an accidental kiss…

Xiao Yan: Did I fall for him? But he’s a man!

Maya: Who knows…. maybe it’s the other way round?

- Description from Novelupdates