
Ohh forgot to add about that one thing, I think the reason for that would be because Delkira sealed his demonic side and wanted Iruma to live as a human, and the reason why Sullivan picked Iruma is because he, who was a close aide to Delkira, may have noticed something in Iruma that remined him of Delkira. But all in all this is just my own thoughs/ theory. HAHAHA

love yr theory and its also interesting to note that whenever there are flashbacks of iruma's parents they are always just bodies and no face. it feels like even iruma's memories was manipulated and that these people were planted or the irresponsible babysitters but iruma was led to believe theyre his parents. but i have a strong feeling that when described, iruma could never describe them.just their personalities. that or delkira was replaced in iruma's memories with these people. it kinda fits? like their personalities were a spot on for delkira's nonchalance, happy go lucky attitude, kinda.
THAT or i have a theory that iruma was chosen by delkira, not really his bio son or anything. but was chosen to be his successor and delkira transfered his powers to iruma but they are sealed. and since iruma's body and mentality isnt ready for demon powers, as he is human, alicred acts as his mentor and guide iruma to get accustomed to demon powers until he is ready to unlock the powers delkira sealed in him. gosh cant wait for the revelations... but almost want these chill moments

True. I have that theory too from before.
Now, I am thinking. What if:
1. He's actually Delkira, sealed his power together with his memories, and living as a human. Since he's really powerful, creating that body is just a breeze.
2. That Iruma is his reincarnation. Like, he died but instead of being reborn as a demon, he was reborn as a human. And his power remains dormant. And maybe someday, something will trigger it to awaken.
Just wanted to share this is regarding if Iruma purely human.
I have a feeling that Iruma maybe a half demon. As I was re-reading the manga, I have always though that what if, Iruma is the child of Delkira.
So hear me out, here is what I thought,
1. In the first few chapters we did see parents of Iruma, but what if it they really are not the parents of Iruma? what if Delkira tried to manipulate their minds and made them think that they have a child, and that child is Iruma.
2. When Iruma recieved the Gluttony ring, and raised his rank, there was something that pops out in the ring and once he could talk, it introduced himself as Alicred, and if you read it backwards its pronounced as Delkira. (Remember though that there is no letter L in Japanese and when it is pronounce it is changed to letter R)
3. Ali- san has always protected Iruma through as through. But it could also be possible that Ali-san may have done somthing that made him be stuck there.
4. During the Harvest Game, we saw a glimps of Delkira appearing, and saying to Iruma, "So, your the one."
5. When Iruma was trting out the machine to determing how much magic he has, his paper had a mark, and once Baal received that thanks to that Spider demon (forget his name), he said that it was the mark of Delkira.
This is just my thoughts though. Maybe the reason why Delkira dissappeared from the underworld was because someone, I mean a human was able to summon him and who knows maybe fall in love with a human and all that and didn't yet go back to the underworld.
Well, I am quite excited where the outcome of this manga goes, cause so far this manga has never failed to amaze me.