Because the Devs needed to set up Lucifer as the villain and the one you’re fighting against, while still having him remain as a viable romantic interest.

So the result was that Lucifer and MC have literally the most sexual tension in the entire game, while still being at each other’s throats 95% of the time.

The spy vs spy like action of Lucifer inviting MC to dance and then pulling them far too tightly against him and threatening them unbeknownst to the rest of the party.

Lucifer asking MC to meet him alone in an abandoned classroom only to tell them ‘while he is sorry for trying to kill them, they deserved it.’

Like from day one these two locked eyes and were immediately ready to throw down. Lucifer is so much more powerful than MC and yet MC is over here like “Death before dishonor! Never surrender!”

It’s also hilarious how much of a punch clock villain Lucifer was, like anytime something wacky happened to him(I.e. the body switching incident) Lucifer is suddenly MC’s long-suffering friend, who hangs out with them in class going “Can you believe this shit? This is what I go through like every week.”

Say what you will about the obey me devs, they know how to do enemies to lovers. All their interactions felt like:

Lucifer: You’re insufferable

MC: You’re a tyrant

So in all text I’ve seen hell didn’t exist before Lucifer fell, but in om while, the devildom is assumed not to be as put together when the boys fell it still existed.

However in the book of Enoch(part of the dead sea scrolls and not considered canon by many but still provides interesting context and was supposedly penned by the great grandfather of Noah) and the book of Daniel(considered mostly canon by Christians and Jews). There is a group of angels that fell before him called the watchers(irin) or holy one(qaddiysh). In the book of Daniel(written sometime between 400-200 B.C.E) the watchers are solely in the service of god as spies and messengers sent specifically to give Nebuchadnezzar prophetic dreams. This is the first reference to angels by individual names and identities separate from god. In the book of Enoch(written 200 -100 B.C.E so later on in the book of Daniel) the irinor watchers refer to the same group of celestial beings but split them into the disobedient and those who punish the disobedient.(I’m working my way through it but there are specific angel names but there were 200 disobedient ones in total)

The disobedient are called so bc they fell(ba dum tss) in love with humans and wished to have human bodies because of this then birthed the Nephilim a race of giants referenced in genesis, and the book of giants(this is the most biggest evidence for the books of enoch to be canon). However, you’ll notice that their reason for rebelling is far more similar to Lilith’s reasoning then the biblical reason for lucifer to fall(I’ll talk about the similarities and differences in Biblical to Om Lucifer’s reason for falling later)

Moreover when the watchers fell they did not go to hell but lived and were punished among the humans. So I would argue that om switched the intentions of falls. So that the desire of a will and ability to create(something only given to god and humans) was the intent of the Irin who(specifically the demon king) used that stolen ability to create the devildom(and Diavolo edit:I realize this is proven wrong by the current chapters I'm not totally caught up though)

While Lucifer and his coup of heaven was because of god’s persecution of Lilith for her relationship with the human. This clears up why the devildom existed before lucifer fell, why human society existed while the brothers were angels, why barbatos(who has been stated to be a fallen angel) was fully a demon at the time of the fall and clears up Diavolo’s creation despite him having no mythological equivalent(I theorise he was born similar to Satan but his core sin is curiosity and was created bc the watchers stole some of god’s ability to create(edit:disproven but I still think it’s a cool idea so I’m leaving it in)

Also I think Satan was born both bc of Lucifer’s rage but also bc in the moment just before he fell Lucifer successfully took the throne of god and in that one instant used that power of creation(most likely unconsciously) to bring forth Satan. As the only unanimous way demons are created being that they are fallen angels this means only Diavolo and Satan are beings not created by god

Endnotes and other cool facts The watchers also fulfill a prometheus role by teaching humans how to do magic,use cosmetics, weaponry, and ect so that god flooded the earth to get rid of both the nephilim and these inventions

The fall of the watchers is also referenced in the damascus document which is an old Jewish document, Grigori are also referenced in this but I’m not sure if that refers to the nephilim or the watcher themselves