Purple River: Immortality Gene at the Start

[Purple River fanfic + system + filling plot holes + behind-the-scenes boss + invincible flow + power fantasy] Lin Junyu transmigrates into the world of Purple River, becoming the third son of the 11th emperor of the Radiant Empire. Good news: he transmigrated into a novel world he's familiar with. Bad news: he transmigrated too early, so the plot he knows is useless. Fortunately, he bound a life choice system:

Life Choice System bound successfully.

At the start, he obtained the Immortal Gene:

You have acquired the Immortal Gene.

Walking through the river of history, Lin Junyu discovers this world is not simple. Demons and half-beasts actually carry human genes? Why has Prince Zuo Jiaming lived for over 300 years without aging or dying? Years later, gazing at the stars, Lin Junyu sits on a golden throne, watching his three adopted sons wreak havoc everywhere, and laughs: "Hahaha, they are all my bravest sons. I'm just an ordinary old father like anyone else." Then, with a gentle wave of his hand, a planet is directly shattered by Lin Xiuyu.