Age
The lone wanderer had casually walked into the Court of Burning Tears' temple, a refurbished and rededicated Catholic church, as if he owned it, and had demanded to speak to "the one in charge". The Arab was now standing in front of Dread Priestess Membo, the court's tyrant, with a retinue of six fell knights surrounding the two. The dark-skinned woman grinned indulgently, planning to soon skin the stranger alive for his temerity.
The Middle Eastern man spoke to the tyrant in a clear, firm voice, with a hint of Arabic. "I wish for you to stop sending your... people... into the area called the Everglades. That is my domain."
The Dread Priestess laughed openly, and was joined by her attendants. "Oh really, is that all you be wantin'?" Her smile and friendly, thick Jamaican accent belied the cold light in her eyes. "If that be the case, then, I am sorry to have bothered you man. I'll call my soldiers on their cell phones and summon them back here right away." More laughter from her retainers.
"Good," the man said, impassively, keeping his dark eyes on hers. "For the fallen citadel you are looking for there is mine."
At this, Membo sneered. She nodded to her men, tired of the game. Three closed in on him, taking his arms. With an almost casual movement, the Arab shook them off; one was tossed to the floor ten feet away. Before the Dread Priestess could do any more than to stand in surprise and outrage, the man lifted his arms and spoke Enochian -- words of great power none of the attendees had heard since before their consignment to the Abyss eons ago. Waves of flames poured forth, instantaneously filling the temple and spreading out into the streets. Space bent around the Celestial and he disappeared, leaving Tyrant Membo, her knights, and the other demons not quick or skilled enough to save themselves to burn.

While it's accepted that the Earthbound are the only ancient demonic creatures on earth, and the only fallen running around are those who escaped from the Abyss just recently, this needn't be the case in your games. Demons have been summoned from the Abyss by selfish and shortsighted magicians for thousands of years. While some escaped servitude and became Earthbound, no doubt other fallen took the bodies of their summoners or other mortals as their own. Most of these demons were destroyed by hunters, supernatural opponents and their own carelessness, more so than "modern" fallen that at least have the support of others like them. A few particularly careful demons could survive, building thrall cults and accruing power in secret. Few would have survived to the modern day, but those that have are invaluable allies and implacable enemies to any infernal court. However, they may feel little or no kinship with the weak, amnesiac things that have so recently flown forth from the Abyss, and none would be so generous as to simply hand over the fruits of their efforts to upstarts. In any case, even the rumor of a demon from the time of Mohammad passing through an area will cause a stir in local infernal courts... Such demons are rare, far fewer in number than the Earthbound. When a demon arrived on earth (and what host he ended up in) would flavor his outlook and attitudes in many ways; one summoned during the Dark Ages would be paranoid of religious figures, while one possessing the body of a Confederate soldier may still entertain racism, chivalry, attraction to family members and other Southern virtues. And the longer a Elohim's stay on earth, the less likely he is to run across other fallen or to cooperate with them. The oldest demons have necessarily made paranoia and secrecy ways of life, proven by their continued existence, and they aren't likely to suddenly switch boats in midstream. Such creatures are so insulated from events of the world around them that they may not even know of Lucifer's recent appearance, or the Abyss' mass exodus following the Maelstrom. They also have the most to lose from discovery, as others will either try to sway such vast monsters to their side or take their hard won boons for themselves.

As one ages and gains experience, be he mortal or demon, he becomes better at what he does. A fallen angel's growth is somewhat different from a person's, however. As the Elohim experiences gradual self-realization, and awakens to his vast Celestial nature. This is much like brushing away the dust covering a vast monolith representing ancient memories. While it's certainly not beyond a demon to learn new things, an Elohim is more likely to realize he knew how to do something all along while practicing a what he thought was a new skill or Lore, or "wake up" to discover he has rediscovered some ability. No matter how much is brushed away, however, there's still more of himself covered by time and mortal limitations, much more than can be uncovered in a mortal's lifetime.
It's fortunate for demons, then, they have much longer than that. At least potentially.
The Age Background allows Storytellers to populate their Demon chronicles with venerable beings of vast power and influence, with the oldest rivaling Earthbound in influence and power. Optionally, player characters can play the roles of older fallen if the Storyteller wishes to tell epic stories, though I stress caution here. Unlike Arcane and Demon Familiar, Age isn't appropriate for all chronicles, and should only be taken with the Storyteller's express permission.
The fallen explores the mysteries of this world and relives memories of eons past, and understands himself better and awakens more of his Celestial nature. Therein lies great power; ancient demons are incredibly powerful beings. (Cosmic Power offers systems information on the degrees of power old fallen can attain.) The Elohim's connection to the world of mankind fades as he sees first individuals, then entire nations born, only to be blown away by the winds of time. Valued possessions are lost or wear away. His host's identity and memories are subsumed and eventually completely replaced by that of the demon. And worst of all, he sees the world he helped create at the Dawn of Time slowly wind down like an abused, neglected machine. Hunters, other demons and various supernatural factions take their share of these great Angels of the Abyss, though more Elohim are claimed by the Tormented howling in their souls -- all the louder from the steady erosion of their hosts' identities.
Aging Systems: There are restrictions on freebie points granted by Age. First, the player must first generate a character according to the rules in the book (or by my even better house rules, if you'll forgive the plug), buying the Age Background in the process. Note: a character's Age background can never exceed her Legacy; rather than being a prerequisite, Legacy reflects the process of the fallen regaining access to the memories of prehistory as he ages. (In other words, a demon a few centuries old is bound to recall something about himself.) Then, after the character is completed, Age freebies may be spent; these extra freebies are not added to the character's initial freebie points. In addition, the following traits can't be purchased or improved with Age freebies: Age, Arcane, Familiar, Legacy and Paragon.

●	Fifty years old: +1 Faith, +1 Torment; five extra freebie points; -2 mortal Background dots.
●●	One hundred years old: +2 Faith, +2 Torment; ten extra freebie points; +1 diff to mortal host's Ability rolls; -4 mortal Background dots.
●●●	Two centuries old: +3 Faith, +4 Torment; fifteen extra freebie points; +1 diff to mortal host's Ability rolls; -6 mortal Background dots.
●●●●	Three centuries old: +4 Faith, +5 Torment; twenty extra freebie points; +2 diff to mortal host's Ability rolls; -8 mortal Background dots.
●●●●●	Five centuries old or older: +5 Faith, +6 Torment; twenty-five extra freebie points; +2 diff to mortal host's Ability rolls; -10 mortal Background dots.

The Wages of Sin: Whoa, hold on there. Before you start investing all your dots in the Age Background (and players, you need to ask your Storyteller first), being a demon thrust into this world long ago isn't always good. Though a juggernaut in terms of power, an Elohim's connection to mortals becomes weaker as more of his angelic nature is realized. He's also a lot more acquainted with Torment, which has continued to chew away at him long after his escape from the Abyss. Many older fallen are utterly inhuman, both physically and mentally, unable to relate to mortals and forced to move only among their fellow damned.
Only use the following rules when generating older characters, or when simulating significant downtime; characters that are played from youth to ancient status won't have points added or taken away, as their in-game experience will probably reflect the following.
♦ Torment: As the host's identity and memories fade, so does the psychic bulwark that helped hold back the flood of anguish. Plus, whether heeding the call of power or merely trying to survive, demons often find themselves acting in ways that further feeds their inner conflict. Thus, the Age Background is added to the character's permanent Torment; those with an Age of 3 or higher gain an additional point of Torment on top of this. If this increases the character's Torment to 10 or beyond (or to an unacceptably high number), the player can choose to instead sacrifice one dot of permanent Faith to remove a dot of Torment.
For example, Mike is creating a fallen character that is one hundred and fifty years old. As Mike's character has an Age of 2, he gains two dots of permanent Torment.
♦ Disassociation: Part-and-parcel to having possessed a mortal's body, a demon's ego and desires supersede that of the mortal. While at first the angel has full access to the mortal's memories and abilities, after awhile these begin to fade as the Elohim's identity and capabilities come to the fore. His aptitude in Abilities inherited from the host fade, though those innate to the demon remain as strong as ever; half the character's age (rounded down) is added to difficulties when using Abilities retained from the host. In addition, Dots in the host's Background are lost (typically Allies, Contacts, Influence, Resources); for every dot of Age, the character loses two Background dots. This means that players of very old characters will have to dump a lot of freebie into Backgrounds to make up the difference if they want the demon to have any mortal ties. Such is the price of power. The Storyteller and player will determine which traits are associated with the demon's host, and which reflect the fallen's own capabilities.
Mike's character loses a total of four Background dots, and suffers a +1 difficulty penalty when using his host's Abilities.
♦ Learning Curve: Storytellers may impose a slower rate of progression on older fallen; I think becoming a static thing, set in one's ways and less able to learn new things, is a danger for all immortal creatures. (Which is why I use this system for elder vampires and wraiths, as well.) A method to simulate this rigidity is to add the character's Age (or optionally, the number of centuries he's been active) to his experience point multipliers (so a demon with Age 2 would require [level x 7] exp to increase a Lore, [level x 6] for Attributes, etc.). Another, simpler way to do this is to reduce the experience a demon earns proportionately to his age, though he always earns at least one experience point per session.

Arcane
Qui'lath of the Lost Moment looked through the dusty stack of papers, again, squinting from the glare the bare bulb hanging above threw over everything and through the smoke from her cigarette. She had to get in contact with this "Lord of Rusted Blades." He knew who destroyed the Court of Burning Tears, someone that could help her bring destruction to the other courts and even the Earthbound. This was information that Qui'lath badly needed, but she didn't have this demon's Celestial or even a full mortal name. She knew his first (or maybe middle) name was Jean, pronounced like "John", and the last name was something else French. After two weeks of canvassing his old neighborhood, she managed to uncover the fact he was born here, in this now-closed Catholic charity hospital in the Irish corner of Brooklyn. Or at least, that's what three people told her, while two others said different hospitals. But, three matching accounts gave Qui'lath some hope, so she figured here was her best place to start her investigation fresh.
It was some time before something caught the corner of the Fiend's eye. She got up from the warped wood chair and walked over to two garbage cans sitting next to some burnt boxes and blackened, old frayed wire tipped with new tape sticking out of open outlets. In the trash was the burnt remains of paper, apparently the result of an electrical fire that happened years ago. And Qui'lath figured -- no, was certain -- Jean's file just happened to be among of the ones that burned.
The short brunette sighed and walked out of the room, taking care to throw her lit cigarette behind several boxes in the back before leaving; the frayed patterns of Creation told her this wouldn't be noticed by anyone until it was too late. If this place was of no use to Qui'lath, then it would of use to no one. The anger in her somewhat sated by the act, the Neberu headed for the old nun that let her in. Though she claimed to have no memory of Jean ("That was so long ago, child, and so many children have passed through here..."), the Ravener was sure there was something the wrinkled old crone could tell her before she burned along with this wretched place. Qui'lath was low on Faith, anyway.

A fairly common trait for experienced demons (and likely part of the reason they're still around), Arcane grants a character a certain degree of anonymity. Fallen with moderate scores in Arcane are easy to overlook, and are difficult to find if they don't want to be found. They leave spotty and confusing paper trails, and clues pointing to them often lead to dead ends. Those with high scores in this Background are easy to lose even when looking away from them for but a second, for they tend to melt into the crowd and leave no trace of their passing. People asked to describe the individual later -- if they remember him at all -- give differing accounts as to his appearance, clothes, and actions.
The game effects of Arcane are as follows. The character's Arcane is subtracted from others' die pools to find the subject or gain information about him (notably Investigation and Intuition), or even guess as to his motives or true nature based on extraneous information. This includes others' attempts to dig up the demon's Celestial Name or True Name.
However, no amount of Arcane will help a character in Revelatory form, launching flaming bolts at foes, or otherwise making a spectacle of himself, nor does it function as an "invisibility power." Arcane's effects, while subtle and passive, doesn't directly influence others' minds (so a demonic nature or high Willpower is no proof against it). Rather, it seems to influence fate and coincidence in such a way that the character manages to avoid scrutiny by being precisely where someone isn't paying attention; even when the character isn't nearby, it increases the probability that information on him will be lost. So even ostentatious characters are easily ignored or forgotten, as viewers either happened not to pay attention to them or were more focused on details than the whole, while clerks seem to just have a way of misfiling or deleting vital information about them.
Note this Background might not be beneficial to the demon all the time, and it can't be "turned off". Potential allies and thralls may give up looking for the character after a long a fruitless search, for example, and a demon getting emergency medical attention when the computer insists he doesn't exist can be problematic.
Arcane doesn't interfere with the demon's maintaining thralls. Once a pact is made, a thrall can find his way to his master as if the fallen angel had no Arcane. A character that possesses a demon's True Name can ignore his quarry's Arcane, as well.

x	While he doesn't necessarily stick out like a sore thumb, the demon isn't hard to find.
●	The character is difficult to pick out of a crowd and manages to avoid casual scrutiny, though it's not hard for a determined person to find him.
●●	While not anonymous, people often have trouble remembering the Elohim's name and face after he leaves; details escape them. He can reliably avoid detection.
●●●	The demon is easy to miss, even when he's being actively pursued. His Social Security number and birth certificate probably disappeared years ago.
●●●●	It's almost impossible to find the character when he doesn't want to be found -- and even if he does. Friends forget to meet him and constantly lose his phone number, forget his address, and so on. The fallen is a perennial member of the local infernal court, largely forgotten when not present.
●●●●●	Who, again?