I Transmigrated Into a Novel and Became the Protagonist's Patchwork Brother

Transmigration, multiple female leads. Inner thoughts, though not all of them are inner thoughts. More details will be added later. Qin Tian wakes up one day to find himself the male supporting character in a novel. After accepting the System, he vows to help the protagonist with all his heart, becoming a brick the protagonist can use wherever needed. But in reality... When he meets a heroine: This girl is gorgeous. There's no way I'm letting my idiot big brother have her. I'll take her instead. Find him someone else. When he finds an opportunity: This is pretty good. Too bad Big Bro can't make use of it even when it's handed to him. I'll just have to take it myself. (Overjoyed.) Gradually, something goes wrong with the plot. The heroines seem to have lost their minds, all throwing themselves at him. The stunning campus beauty: “Qin Tian, you're so handsome!” The gorgeous landlady: “Qin Tian, I think you're a better leader than your boss!” The mature queen of pop: “Little Qin Tian, what do you think of me?” Surrounded by beautiful women, Qin Tian turns dark: “Master! I've seen the light! I'll be the protagonist instead!” And from then on, he goes down a path of no return...