My Devoted Male Supporting Character Persona Can't Crumble [Book Transmigration]

After transmigrating, Ming Shi found himself in the body of a stunningly handsome shadow guard, tasked with protecting a beautiful young lady whose parents had both died. She was delicate and helpless, and the two had relied on each other for years. She often sent him meaningful glances and smiled at him. After the System told Ming Shi that the young lady would be able to make an antidote for him in the future, he steeled himself and committed to the role of the devoted male supporting character. At the young lady's coming-of-age ceremony, a young master from a prominent family caused a scene and declared he was breaking off their engagement. Ming Shi made a dramatic entrance to rescue the beauty. But according to the plot, if he wanted to live happily ever after with the young lady, he would have to compete with a domineering prince, a gentle strategist, a cold poison doctor, a wickedly charming demon lord, and other top-tier handsome, rich, and powerful men. For the sake of his deeply devoted (antidote-brewing) persona, Ming Shi gritted his teeth and gave it his all. But he never expected these men to chase after him instead, willingly becoming his devoted admirers and fighting tooth and nail just to make a cameo. And the heroine Ming Shi had always protected... turned out to be a man. Later, Ming Shi finally realized this was a fanfic where the heroine had been gender-swapped. And he was a bona fide Tom Sue. Ridiculously handsome, straightforward, level-headed bottom x brooding top who is a master of disguise Reader's Guide: As is customary, one-on-one, both pure, happy ending. Strong characters. The bottom is an incredibly powerful fighter, while the top has the script of a great heroine. He regains his male body midway through the story and absolutely loves teasing the bottom. Theme: Be a model young man in another world