Logically speaking, it should be the little sister, it is the right occasion to humiliate her, no? Some other person seems too out of the blue and the stepmother has her own banquet to deal with.
i dont think thats exactly the case. we know who LHC's father is already, but it's probably something like they are ancestor and descendant is my guess. or something like that anyway.
Spoiler for the demon king’s relationship to LHC. Read at your own risk. Or don’t read at all. That’s also an option. . . . Actually, the demon king is LHC’a grandfather from his mother’s side. His mother is the demon king’s daughter.
Let’s just say that, if sui is going to be a male (probably not), and he is now a baby slime, when he turns into an adult slime, he might be able to shape shift, into a man... and if that happens then (≧∀≦)
Oh.... i think we have official evidence from the Shen yin person that this manga is going to get gayer ( の ▽の)╭