Feng Huai transmigrated into the story to give the protagonist an overpowered boost, but got the target of his strategy wrong. So he went down the road of raising a nobody and crushing the protagonist, with no turning back.
Feng Huai: "Hah. You insignificant ant who doesn't know your place. You think you can become the protagonist just by working yourself to the bone, leveling up, killing monsters, making yourself look good, and picking up gear? If you get in my way, I'll destroy you until not even your bones remain."
The protagonist: "..."
Theme: A rivalry between a nobody forcibly given an overpowered boost and a genius who works desperately hard, born from a case of mistaken intentions.