Headcanons for how demons and demon hierarchy works in obey me according to me because I love seeing takes so I figured I might as well give my own
This is barely even a headcanon but demons are hella hard to kill and as you go up the ranks it just gets harder and harder to wound and kill them. So a low ranking demon is already pretty hard to kill but a high ranking demon is damn near invincible
Obviously all demons tend to live a very long time. Lower ranking demons usually make it to a few hundred years but some can make it to a thousand, your average mid ranking demon makes it from thousands-millions and your high ranking demons are nigh indestructible and make it very very very long times
They all appear attractive towards humans but there are some that don't just benefit from the glamor and there are some that really benefit from it, a more naturally beautiful demon is obviously going to appear more attractive than a more average demon
The brothers are not the only fallen angels in the Devildom, there are plenty of fallen angels scattered about. Whether from the Celestial war or before or after, all of different statuses
The social statuses in the Devildom go: The sleeping demon king, Diavolo and Barbatos, the Brothers, the Nobility and other high ranking demons, mid ranking demons, and low ranking demons
Now starting with the actual headcanons - lower ranking demons (some of these may be mixed with canon)
Lower ranking demons don't really take full forms but are rather something more akin to imps, the little d's for example would represent the lower demons quite well
They're not very intelligent and are mainly used as servants, the house of Lamentation I would imagine would actually have some running around since the brothers are supposed to have high statues - Pretty much all high ranking demon houses employ them, you'll find them running around the Demon Lord's Castle too
They're very common and their forms are pretty animal-like in appearance
I also headcanon that demons actually have a real demon form that looks more like their assigned animal and that form is the lower ranking demons general form because they're not strong enough to materialize proper human and humanoid demon forms
The lower ranking demons also do the general jobs such as deliver packages and mail and clean and cook and etc (this is the case in restaurants and other establishments too) and you are overall expected to treat them well even if they're not neccesarily respected
Low ranking demons don't breed they just kinda show up or are the souls of people who made deals with demons or really wicked people being punished for their awfulness in life
Mid ranking demons are the general population of the devildom and normally what you think of when you think demon
Demons are in general bigger (not including low ranking demons) and stronger than humans and I imagine that the average height of general demons in their human forms falls somewhere on the 5'10-6'2 scale though there are demons that are in general shorter or taller
Their humanoid demon forms are slightly larger than their normal human forms and their proper demon forms are around that same size
They usually just show up ala satan style or just show up randomly in general but they can breed
Demons have a very specific set of things that they have to go through to breed so there's no such thing as forced or accidental pregnancy for demons
And you have to have a very strong support system as demon kids are very much a handful so it's expected to be an all hands on deck situation
I also headcanon that demons are expected to stick together in large groups as the devildom is obviously not the safest and everyone in that group is expected to take care of a kid if there is one
All demons are assigned a sin and catgorized based on that sin (the brother that is the lord of that sin is considered to be the main authority only bowing down to the demon king/the current regent) for example inubi and succubi are obviously under the authority of Asmodeus and labelled as "lust demons"
The sins are overall treated equally and you're not going to be treated better or worse because you belong to a certain sin, though different sins tend to take up different industries
For example lust demons make up a lot of the entertainment industry, greed demons make up the financial industry and so on so forth
Mid ranking demons actually vary significantly in terms of power and status, plenty of them have pretty impressive roles and plenty of them also hold very low statuses
And demons don't have last names in general so mid ranking demons just give names to their kids
High ranking demons all tend to make up the nobility tho there are some exceptions (most of these examples are the high ranking fallen angels who didn't get noble positions but made a name for themselves otherwise)
Their human forms are in general quite a bit taller ranging from 6'2-6'6 on average and their humanoid forms also gain a lot more height
Their true demon forms are the most monstrous and terrifying looking and a lot larger than either of their previous forms
I headcanon that while demon nobles are nigh indestructible they still keep an heir or two around since the Devildom is very unpredictable and they usually send these heirs once their sufficiently grown to the capitol (where RAD is and the brothers, exchange students and Diavolo are) to make money, garner influence and gain powerful allies (especially the brothers)
Nobles have a system of a family name - Like say Duke Valefor might name his heir Valefor because that's considered to be the family name and holds prestige. Spares are also given family names but those names don't have as much prestige because the spares are expected to serve the family in some sense, usually to be married off for the sake of alliances. Diavolo's mother was one such case, she came from a very prestigious high ranking family
And while nobility tend to hold and rule over land there are still plenty of high ranking demons who don't but rather hold their authority through a position, for example Mephistopheles and his family
High ranking demons are called Devils
With the Brothers, Barbatos and Diavolo being Archdevils because of their position at the very top
The demon kings tend to be deified by the population and treated like their word is law and the royal family are in general the most unquestionably powerful in the entire Devildom
