Forty Millenniums of Cultivation - Chapter 4: Fiend Blade Peng Hai

Year 2056, in a city in the Yuan Jiang Su Jin area. On top of a ruined, shattered six story residential apartment sits a teenager wearing a combat vest, militaristic trousers, and alloyed battle boots. On his back is a hexagonal shield and equipped is a blood-shadow battle knife. He sits there silently on the edge of the roof. At this time, the sparkling sky was shining and there was a refreshing breath within the air that blew towards him. However, there was only silence within the ruined, deserted city, with an occasional howl that makes your heart skip a beat.

- Description from novelupdates

“Jiang Yu transmigrates into a novel and becomes a side character in the book.

Perfect. That’s what people call Princess Elysia. Blessed with rare red fire magic and trained by the best, she’s the shining jewel of the kingdom of Arvandor. But perfection has a price. When the ruthless Demon Queen Malvoria sets her sights on Elysia, all hell breaks loose—literally.As Malvoria’s army lays waste to Arvandor, Elysia’s life is shattered. Her beloved father, the king, is slain, and her once-peaceful home becomes a battlefield. Forced to flee with her girlfriend, Zera—the fierce daughter of her magic teacher—and her mentor, Lady Seraphina, Elysia’s journey of survival begins.But Malvoria wants more than just a kingdom. She wants Elysia, and nothing will stand in her way. As Elysia’s hidden powers awaken, an unexpected and dangerous attraction sparks between her and the demon queen.

This is a cliché story about two young people saving the world.