Does the ML have pink hair?
I don't remember...
not a novel so it might not be what youre looking for, but its kinda the same(??)
https://www.mangago.zone/read-manga/i_have_to_be_a_great_villain/
Someone from Novel updates forum found it for me , it's The Villain Slaps the Protagonist’s Halo
I'm totally checking this out
It's a quick transmigration novel where the MC/shou was punished by being forced to transmigrate in different worlds until something happened with the system and the mc broke free from the control. Afterwards, MC retaliated againts the original plot and main characters. The ML/gong is very devoted. There's this one arc where the MC transmigrated as the emperor and he learned that the gong was one of the shadow guard when the gong returned from war.
I remembered that I'm the real world, the mc was framed for several murders and was punished to suffer by world hopping and getting tortured by the plot. The gong tried to rescue the shou by entering the world the shou is in.
I badly want to reread this