Spoiler Free Lore Dump!!!

So, on the surface, the setting is near identical to modern life Earth, but there's little cultural differences so...

It's Time To Infodump about The History of Hell!

(and also how surnames work in Hell bc I'm a nerd)

So in Hell, human inventions have been slowly filtering in over the millennia, but historically, it was all the Goetic princes ruling, largely due to the fact they were simply physically strong enough to hold their title.

All the more powerful Old Guard are massive. Powerful demons are very tall in general. For example; Lucifer is around 7' tall before horns. Asmodeus and Behemoth are almost 8'. Meanwhile, your average demon is just... human sized. They’re basically as physically large as possible before their bodies just aren't able to support their own weight and mass anymore.

The current cast, to scale with each other.

But- due to the slow trickle of human technology coming in over time plus the second Western Industrial Revolution creating a lot of very advanced weaponry (and just enough technologically savvy human born demons remembering enough of their past), there was a messy a brutal civil war because a lot of demons suddenly had the strength via technology to even the playing field. During this period a lot of the older Goetic Kings and Dukes and Lords went missing or were killed, creating a power vacuum that was eventually filled by The New Goetic Lords and their more modern domains, like Mr Belfry and his city sized theme park based off his cartoons, or Callafia and her Manhattan sized Vegas style casino.

Behemoth and his more average sized partner, Oxpecker.

Also- over time, it became common or trendy to give your child a powerful name like one of The Old Guard, often times adjusted or shortened in cute ways. That's why Asmo is named Asmo. It's like naming a kid Arthur or Kennedy. (Yes- I knew someone with the first name Kennedy growing up ) Bill also sometimes gets mistaken as Bael because of this. (Nah, he's not William, he's not Will, he's not even Bael. Nope, he's cursed with just... Bill.)

But- all this lead me to thinking about how would last names work in Hell and how surnames call back oftentimes to old alliances or occupations.

So in Hell- you basically have a title.

It started off with which house of which Prince (and thus which sin) you were in alliance with as well as anyone notable that you might be related to and any notable things that you have done. But- with the loss of the feudal structure in hell, over time it's evolved into an identity marker. You still put the sin you feel the closest affiliation with, but you can also put familial associations (chosen or not, it's up to you), accomplishments that you're proud of, history that you feel you need to emphasize, things like that. (It's actually quite suspicious if someone doesn't have some sort of affiliation in their title.)

So- for example, Valentine's full demon name is Party Valentine, Domain of Luxuria, Human Born, Drummer of The House of Belfry.