Maybe Sullivan had to pick the "least human" human to bring change to the Demon World idk ╮(￣▽￣)╭
Iruma is definitely an unusual human xD Those reflexes are only something one could wish for, and more importantly, I still can’t believe he grew up to be so kind, sweet, positive, and have the willingness and enthusiasm to learn things with such neglectful parents. I can’t wrap my head around it still lol. They may be following the laissez faire ( I most definitely butchered the spelling xD) parenting style but it’s rather irresponsible with how they were going at it . Heck, I don’t sense resentment from him; he ain’t that type of kid …even with the senpai who wanted to hurt him ╮(￣▽￣)╭
Compilation of theories of Iruma-kun, like what if the ring of gluttony that iruma is using is eating his humanity and little by little he's changing into a demon, because he's showing some changes like he doesn't have to paint his nails black/blue, and I also have another theory about delkira sama(former demon king) I think delkira sama is arikured because delkira sama became missing and maybe somebody betrayed him and he hide himself inside of the ring of gluttony, and delkira sama and the demon world that he created has some similarities with the human world like the dem-dol similar with idols and much more, I also think that the 13 crowns future would be iruma's classmate because of their mentors but this is just a theory though, iruma-kun is possible to be the demon king because of the prophecy because why would Sullivan pick iruma when their are alot of different humans he can choose from.