Tensei Kenja no Isekai Raifu ~Daini no Shokugyo wo Ete, Sekai Saikyou ni Narimashita~ - Chapter 15 - I Accepted a Quest

In the waves of steam and machinery, who could achieve extraordinary? In the fogs of history and darkness, who was whispering? I woke up from the realm of mysteries and opened my eyes to the world.

Lord of the Mysteries, part two.

In 1368, at the end of July. Bloody scarlet will descend from heaven.

After a shocking reincarnation, our hero opens her eyes to a new (and messy) world the last thing she remembers is reading Lady Viper’s Vow, a dark fantasy novel about a cruel, misunderstood villainess and her path of doom. But when our protagonist finds herself reborn right in the heart of an attack, she’s moments away from a second, way-too-soon death. Just as she’s about to face the end, a mysterious “system” pops up with a single mission: Level Up or Die Trying. It’s bossy, snarky, and her new best friend. As she levels up into a borderline-cheater powerhouse, she discovers her fate isn’t to be a hero, a princess, or even a sorceress, but to protect the one person no one ever expected her to side with: the villainess herself.

On modern-day Earth, An Lin seems to have been abandoned by God.
When his father suddenly disappears, An Lin is left with his father’s immense debt, putting his life at risk.
After being forced to a rooftop by his pursuing creditors, An Lin is unexpectedly swept off his feet and brought to the ground safely.

After learning that he was saved by an Immortal, An Lin is gifted, seemingly out of pure generosity, the ‘God Of War System,’ and a pass to a new realm.
Follow An Lin as he experiences a whole new world of legends, meets many new friends, acquires legendary weapons and tools, and starts on his path of becoming a powerful cultivator. There is never a dull time in An Lin’s new life with his ‘great’ new system!

- Description from Novelupdates