
People like Sehan irl are some of the people I hate and try to avoid as much as I can. Imagine thinking your partner cherishes you but he on the other hand just thinks you're a "rebound" and a substitute for someone they couldn't be with.
An unsuspecting partner would think they just want you to improve yourself but all the while what they were truly trying to do is mold you to the "image" of the person they "originally" like.
Such disgusting behavior, but in reality, there are a lot of people like this.

This already has 50+ chapters on RIDI so I read some of it to the latest.
Demon seems to actually be the end game and is helping the MC. (And the demon was already interested with the MC even before the contract began.)
Devil was initially contracted by the one playing the piano to get revenge on the MC (ironically it should be that Duke not the MC imo). But the Devil fell in love (I guess) to MC. They joined forces to fix a lot of things in the kingdom too. Kinda badass in a way, on the 50+ chapters, MC has already accepted the Demon ML. (I still need to check what happened to their "child" though.)

Is that cruel crazy duke also in love with the mc??? And his personal doctor seems quite sus, was he the one who killed that fatty??
Also I think the pianist guy cast the curse on mc because he was disappointed with him since he didn’t stop the cruel duke while he was being bullied, mc is not a bad guy and he showed interest in the pianist’s talent and that probably made the pianist happy but was left heartbroken when he didn’t help him, but I’m just assuming all this based on the flashbacks we’ve got so far.
He is of royal blood and was the heir of a kingdom that was ruined, or should I say his royal family were slain and he had to escape and leave that life. So regarding his blood, he is pretty much fit to be the Empress.