
Hold on, I think your initial theory is right. I actually think the prince is the real goblin, too! Our ML may have accepted his role as the goblin, but I think he also said that no one can really know, who's human and who's the goblin. The royal family just decided and everyone went with it. And it does sound like just the thing a goblin would do, manipulate everyone and present yourself as the good one while taking the throne from the real heir. But I guess it doesn't really matter that much in the end.

I was saying something slightly different I was saying is for him to tell everyone he’s a goblin I don’t think there is an actual goblin I thought it was a myth or superstition against identical twins since twins are generally a taboo they believe a beast is residing in them which caused for one of the children to be labeled as the cursed child
So I don’t think either is a goblin just people are against twins and someone has to take the downfalls
What I don’t get is why even tho they knew of the violent tendencies of the crown prince he still stayed the ‘human’ one like if anything I would say he’s the goblin since he’s out to wipe out the humans or something full manipulation tactic right there, but you know what I’m happy homeboy is the goblin cause he probably wouldn’t have been able to meet miss girly otherwise