Milo's feed

Hi , need help finding new sad shounen ai series where the MC is someone's replacement, I want more recommendations please.
Nothing like Black lotus since that role only lasted a few chapters, more like the story thats quite literally just called "Substitute". I want to hate the same through and through until he actually tries to win mc back and has a good redemption ark, I want the angst to last longer than the redemption though, I wanna sob