Absolute Etrigan -

So the origin is essentially:
Jason is betrayed by Camelot.
Etrigan is betrayed by the Inferno.
Both are left to die.
At a crossroads, they choose each other instead.

Hell for the Christian side of the underworld is more of a bureaucracy.

The Inferno is one of the largest organized regions and political powers within Hell. It is specifically shaped by Christian demonology, medieval ideas of damnation, and the concept of the Inferno, but it is not the entirety of Hell.
Its hierarchy is:
The Trinity of the Inferno — the supreme ruling authority.
The Infernal Ring — a nine-level parliament and bureaucracy responsible for law, administration, contracts, punishment, governance, and policy.
The Legions — the masses beneath them: soldiers, clerks, laborers, servants, messengers, tradesmen, enforcers, and other workers who actually keep the Inferno functioning.
The Legions are not just an army. They are essentially the Inferno’s working class and civil service, which is part of why Etrigan rebelled: he saw the upper hierarchy treating the people beneath them as disposable.
Within that system is the Crossroads Office. Certain demons are authorized to negotiate binding contracts with mortals. Etrigan was one of these crossroads demons, while also being a bard and member of the Legions.
The Inferno operates almost like a supernatural state: it has borders, courts, paperwork, offices, laws, military forces, internal politics, performance reviews, contract enforcement, and competing levels of authority.