Some points to clear first:
1: I am the Crowfather for those who don't already know.
The 2nd and last thing is: Desire is NOT Nephilim, he is an Old One, he joined the Nephilim crusade for a reason, to find a purpose, it was he who suggested the Council to Death to stop the Nephilim, Desire was the only reason the Council even heard Death out, when they liked what they heard and the 5 were pledged in service to them.
Desire was the one to comfort Death after Absalom, due him being able to resist Death's punishment he acted as a punching bag for the elder Horseman for the best part of a decade, after Deaths anger was replaced with desire to protect his remaining siblings, and Desire was glad at that, Desire binds the Horsemen together, they all respect and admire him, but love him like a brother, and he feels likewise, even though he is not like them.
He has a group of Hellhounds known as The Vanquishers of Sin, when called he could hold them on a leash and they could sniff out sin a mile away(imagine CoD Zombies hellhounds) if he let them loose, they would jump at said sinners but rather doing any physical damage they would jump at them, and the person would appear to fall down dead and the hound would disappear, when really they have both entered the spirit world and the hound will drag their soul to hell.
Now for his arsenal:
He wields Black Mercy, after persuading Death to allow him to and Mortis fully awakened integrated with his gauntlet and Affliction, and lastly he wields a similar blade called 'Damnation'.
Damnation is a Grand Abomination and gives the soul of the one it kills necromantic power, turning it into a very powerful and valuable currency, an energy source, or a faithful servant bound to the wielder, when fully awoken it can affect the minds of those it is near even when not in combat.
It was the biological weapon of world destroyers, plant it in a realm when fully awakened and the populace would wipe themselves out, also when fully awakened it is only loyal to the one who wielded it last, Affliction & Damnation are not fully awakened until Desire takes on the form of the Headless Horseman (his true form=cover art: he gets bigger, green flames appear and imagine he has glowing green lines going through his armor vertically and he has a crown on.)
Desire also has the power to judge souls as he can see how pure their life and intentions, if he wishes to judge a soul he can summon his Abyssal Throne which gives him the judgement, none can disturb his court, not even his siblings or even the Charred Council, his ruling is final and often swift and brutal depending on the person, they expect to see God and they instead see a hooded human damning them or ascending them, it seems like he had much power, but in reality it is his ability to see into their hearts that the Council thought he should be able to judge any soul he feels is worthy, which isn't very often.
Remember, he is not invincible, nearly, however close but no cigar as you mortals say, why do you come to me for stories anyway? don't you have your INtranet now or whatever? an old man could do with some peace... anyway onto the real story now.
-A couple of hundred years ago, maybe more-
"come on brother! surely there is something you desire?" asked Strife with a laugh.
"I desire to be left alone by you little brother," laughed a humanoid creature, claws not unlike Tiamat covered by a black gauntlet or more like disguised, the gauntlet made it seem like his claws were part of the gauntlet rather than his actual claws.
Also he had rows of sharp teeth only visible when he smiled fully or tried to be intimidating , green glowing eyes and a black helmet(image on Chapter 4 when it's out) when he is on mission, he wears a hood and facemask when not, when he is in battle it was plated with black armor his hair was black and curly, wavy when he wants, he had the height and strength of War, the marksmanship of Strife, the temper of Fury and the agility, near invulnerability and heightened senses of Death, he could twist simple desires into cravings, a demon wants power in his heart? Desire will make the want a need and the demon will kill to get what he wants.
"That was a good one," chuckled Death, the only time they let their hair down was with each other.
"I don't see what's funny... we pick on Strife everyday," smiled War.
"Shut up brother," mumbled Strife.
"Leave him alone, he doesn't need us calling out his... many many... many many many many flaws do you?" laughed Fury.
"this isn't fair!" called Strife.
"Life isn't fair bro, get used to it, after a couple millennia you'd think you'd get it," Desire rolled his eyes.
"War is the youngest here! shouldn't he be the one getting lectured?" asked Strife.
"I may be young but I kicked your ass when I slaughtered those humans!" he pointed out.
Suddenly a familiar voice rung out.
"Oh Horrrrseeeeemeeeennnn!" called the Watcher Panoptos.
"Here we go," said Desire as the Watcher approached.
"The Counnnncil hasssss neeeeed of you allllll," he said in a jeering voice.
"Oh Infernum, here we go," sighed Fury as they all mounted their horses, Desire's horse was Guilt, as from Desire spawned Guilt.
"What? it won't be that bad, let Death and War listen, we can zone out and wait to hear the plan," said Desire with a half smile.
"If you do I will seal you in the Vault myself," said Death, deadpanning his face but his tone showed humour.
"Ehh, could be worse... and we need to ask for a pay rise," said Desire.
"We don't get paid!" said Strife who was confused.
"Exactly!" said Desire as they arrived.
"What would they pay us? souls? weapons? maybe they could replace Strife's ugly helmeted mug," chuckled War, but they all clamped up as soon as they were outside the Council Chambers.
They entered the Chamber for another day on the job as Horsemen...
That is all I can recount for now mortals, leave until next week possibly tomorrow, you will know when to return, because you will favorite this story... and comment with no flames and constructive criticism only, until next time mortals... if you live that long.