I Accidentally Saved the Wrong Villain, So I Ran for It

This is the blurb:

Sang Rong transmigrates into a book. Though he’s become a little kid, that doesn’t stop him from dreaming of finding the male lead, sticking close to him, and riding his coattails all the way to the top.

Soon, Sang Rong comes across a boy being cornered in an alley. The boy is the fiercest fighter and has the most fearsome glare. Sang Rong nods confidently. This must be the male lead, right? No wonder he’s so extraordinary!

Later... Sang Rong: Does anyone else get it? I saved the wrong person. I have to run, and I have to run now!

Xiao Zhuo, the original novel’s great villain, grew up dependent on others. He’s unruly and ruthless, an ungrateful wolf who can never be tamed.

On New Year’s Eve, in the snow, Xiao Zhuo is covered in wounds. His dark eyes are dim, and he’s barely clinging to life. He thinks he’ll die in that freezing night. But that evening, a pair of warm little hands takes his, and for the first time since he was born, he feels kindness.

More than once, Xiao Zhuo has asked Sang Rong with a foolish smile whether he’ll stay by his side forever.

Until the year Sang Rong leaves without a word, and Xiao Zhuo can no longer hold back the cruelty and violence in his heart.

On the night they meet again:

“My Rongrong, you were the one who said you’d stay by my side forever. How can you go back on your word?”

Xiao Zhuo’s voice is light and gentle, as sweet as honey, but the madness in his eyes is impossible to hide. “This time, you won’t get away.”

Sang Rong is tied to the bed at all four limbs, staring in horror. What is going on? Can somebody explain this to me?

Character dynamic: Dark, ruthless, mad top × easygoing, go-with-the-flow bottom

Reading guide: Both leads are eight at the beginning; raising a child in the early chapters; healing and salvation

Theme: I just want to live a good life