(spoiler alert), they do end up together, but it's not a happy ending at all imo. The ML basically ruins Michel's entire family for revenge (because ML was abused) and then spends the rest of his life emotionally manipulating and gaslighting Michel so he never finds out the truth. It's built on pure lies AND Michel never finds out that Ian/Ain was planning to kill him/use him as a tool for revenge before he eventually falls in love with Michel.
(not judging anyone who enjoys this manhwa, i just prefer less toxic manhwas)
@Purple lilies, Michel never got to find out or know about it unfortunately cuz like i said Ain basically gaslighted/manipulated Michel into thinking that everything is okay and that nothing is wrong. Hence why I think the ending is bittersweet (?) for some people. They end up together and end up falling for each other but Michel never finds out some truths.

NO ACTUAL SPOILERS DONT WORRY! But something about the ending (yes the actual ending, not the current season’s ending) pisses me off SO BAD, its so toxic