Iruma's Dad: Derkila

"When a human tries to summon a demon, it is the nearest demon to them that appears to them."

So in this case- It wasn't Sullivan who got summoned by Iruma's parents when they were secretly sacrificing their own son-But the missing Demon King "Derkila"-who just so happened to have been vacationing/hiding in the human world.

Because Derkila doesn't particularly enjoy or even like the taste of human flesh- he decides to adopted Iruma instead.

The kids now forever bonded to him now if he doesn't eat- and his lonely with out his friends and family- so why not have a kid to teach and take care of?

He wants to show off his precious boy to the whole Netherworld!

His boy...

His alone....

OOHH!! Naggy Sully would cry rivers over how jealous he was about to be!

But even with all that, Derkila is happy that he's not alone anymore...

-----
Yes I made the cover.