Zichuan: I Obtained the Immortal's Gene from the Start

[Zichuan Fanfiction + System + Filling in the Gaps and Fixing Regrets + Behind-the-Scenes Powerhouse + Invincible Lead + Wish-Fulfillment] Lin Junyu transmigrates into a book set in the world of Zichuan and becomes the third son of the eleventh emperor of the Radiant Empire. The good news: he has transmigrated into a novel he knows well. The bad news: he arrived too early, so the little plot he knows is no use. Fortunately, he binds to a Life Choice System and obtains the genes of an immortal from the start. As he walks through the river of history, Lin Junyu discovers that this world is far from simple. The demons and half-beasts have human genes in their bodies? Why has King Zuo Jia lived for more than 300 years without aging or dying? Years later, gazing at the stars from his golden throne, Lin Junyu watches the three adopted sons he took in slaughter their way across the land. Hahaha, they're all my bravest sons. I'm just an ordinary old father, just like anyone else. Then he gives a gentle wave, and Lin Xiuyu shatters a planet outright.