Lin Shiyu has been sickly since childhood. Every day, when he isn't being resuscitated, he's reading novels, so despite his young age, he's already familiar with all the melodramatic tropes: tragic love, pregnancy, and stand-ins.
After Lin Shiyu stops breathing in the resuscitation room, System 419 takes him into a popular comic that ended abruptly.
419 sobs into a little handkerchief: [The villain is too strong. The protagonists can't beat him, and the whole team got wiped out.]
Lin Shiyu: "..."
That's pretty bad.
419: [I'm useless! Help me!]
Lin Shiyu says that's totally fine. Then he's dropped into the comic Mechanical Immortality to earn popularity points and fix the plot.
In the original story, the protagonist is a poor boy from the underground city, a destined hero. The main villain is a completely inhuman mad scientist.
But 419 is such an unreliable rookie System that it sends him ten years before the story begins. At this point, the protagonist is only five years old and can do nothing but curl up in a corner, crying and pretending to be a mushroom.
Lin Shiyu: "..."
419 shrieks: [It's over!]
[Don't panic.] Lin Shiyu looks at the villain, who's still in his prime. [First, exchange me a secret identity.]
The readers who had been following the comic were astonished to discover that the heartless Mechanical Immortality had quietly gotten a prequel. They rolled up their sleeves, ready to tear into it, but as soon as they opened it, they saw that the main villain had acquired a kindhearted, beautiful, sickly fiance, and that the brutal, cold-blooded villain was speaking to him unusually gently.
[Wait, man, you've got a wife that gorgeous and you were keeping her hidden?!]
[Who would've thought the villain could almost pass for human before he went bad...]
[Hold on, why is his wife so sickly? I smell angst coming.]
Once the main villain has completely fallen in love with him, Lin Shiyu decisively fakes his secret identity's death. Watching his popularity points shoot up, Lin Shiyu finally gets it: readers love melodrama. Why didn't anyone say so sooner?
So he promptly creates another secret identity to go after the villain and farm points, but now that the villain has lost his wife, he's on the verge of going insane.
Seeing a face identical to his former secret identity, the villain flies into a rage, throws him in prison, and goes completely off the rails. "Who do you think you are? You're not fit to hold a candle to him!"
Lin Shiyu: "..."
Uh-oh. He's taken things too far.
But when he spots the protagonist in the cell beside him, Lin Shiyu immediately changes the script.
A doomed white-moonlight role, a melodramatic stand-in plot, a saint with selfish motives... Watching the popularity points keep rising, Lin Shiyu marvels, "Life is a piece of cake."
Theme: Build a strong body and enjoy good health