Order of the Blackened Denarius

The Order of the Blackened Denarius, usually shortened to Denarians, is an organization of fallen angels who are bound to thirty ancient silver coins, denarii, and seek to bond with human hosts. The coins are said to be the silver given to Judas Iscariot in exchange for his betrayal of Jesus. Of the thirty coins, fourteen are currently believed to be in the possession of the church.

The Coins
Whoever touches the coins is tainted and given power by the Fallen within. The Fallen leads the mortal deeper into its influence by offering, never forcing, until the mortal has surrendered enough of themselves and the Fallen takes control, fully exploiting their weaknesses and undermining their strength. Few mortals can withstand them. They have done so for thousands of years. Michael Carpenter warns Dresden that the fallen don't want him dead, but subjugated.

The Knights of the Cross use a square of white blessed cloth bearing two pairs of crosses embroidered with silver thread to pick up and transport the coins to the Church for safekeeping. However, Dresden and others have safely carried one or more coins through more mundane means, such as gloves to prevent direct skin contact, or storing them in a bag.

In Skin Game, Lasciel reappears after being held by the Church, telling Dresden that the Church's precautions are useless because forces like the Fallen cannot be contained by mere mortals.

The single coins are:
 * Akariel: Its former host is unknown. It was defeated by Thomas Raith and given to Michael Carpenter in Small Favor. Dresden saw its corpse: "'It was black and furry and big, and I couldn’t tell much more about it than that.'"
 * Anduriel: Its current host is Nicodemus Archleone, who's had it for close to two thousand years. It takes the form of Nicodemus's shadow and can change shape in a near limitless fashion, as well as listen to conversations near shadows it pays attention to. It is the commander of all of the Fallen.
 * Deirdre's coin (unknown name): Had a Medusa motif; with very long, titanium-like bladed metallic hair that can be independently controlled and easily stab through people and wooden boat hulls behind them. She was the daughter of Polonius Lartessa and Nicodemus Archleone, and was one of the oldest of the Order until her death by Nicodemus to get through the Gate of Blood in Skin Game. After her death, Nicodemus retrieved the coin.
 * "Green Antlers": Its former host is unknown. It fought with Thomas Raith in John Marcone's safe house and was cut into ribbons by him. He was probably destroyed by the Archive during the battle at the aquarium. It was one of the eleven coins stolen by Thorned Namshiel at Demonreach and presumably given to Tessa.
 * Imariel: Its current host is Polonius Lartessa (Tessa), and has been for a lengthy period of time (Tessa is the second oldest of the Denarians, after Nicodemus). She has a praying mantis motif; she can break into thousands of tiny pieces and regenerate herself. She is the commander of a little more than half of the Fallen.
 * Lasciel: The coin has been in the hands of Harry Dresden from Death Masks until the end of White Night, where he gave it over to the church. Before the events of Skin Game her coin was recovered and given to Hannah Ascher. She's a "rebel angel among rebel angels," and seldom follows the other Denarians; as a result, her coin is not released lightly and Michael notes how strange it is that Nicodemus gave her to Dresden. Nicodemus, when dealing with Dresden's insolence, stubbornness, and refusal to accept authority, comments that Lasciel was the perfect coin for him. She is called "the Temptress," "the Seducer," and "the Webweaver." Michael tells Harry that the nicknames are well-earned, and when dealing with just her shadow Harry has to constantly remind himself what she really is as she knows just what to offer him and how to relate to him. Her sigil is "vaguely suggestive of an hourglass." In Skin Game, she appears on Hannah as purple smoke wrapped suggestively around her naked body with glowing purple eyes. After Hannah's death, her coin is stuck in Hades' Vault.
 * Magog: Its former host is unknown, and it was once borne by Sanya. It was defeated by the Eldest Gruff at Demonreach, and the coin was retrieved by Harry. It has a gorilla motif and was Tessa's "heaviest bruiser."
 * McKullen's unknown coin: Its former host is unknown. It was killed by Jared Kincaid at the aquarium. It was one of the eleven coins stolen by Thorned Namshiel at Demonreach and presumably given to Tessa.
 * Namshiel (also called Thorned Namshiel, or "Thornyboy"): Its former host is unknown. It was defeated at the battle on Demonreach in Small Favor, but his coin was revealed to have gone missing afterwards. It looked like a skeleton, and was Tessa's "sorcery teacher."
 * "Obsidian Statue": Its former host is unknown. It was shot by Kincaid while holding down Harry with "Shaggy Feathers" at the aquarium—a two-in-one shot. It was one of the eleven coins stolen by Thorned Namshiel at Demonreach and presumably given to Tessa.
 * Ordiel: Its former host is unknown. It was defeated by Kincaid at the aquarium. It was one of the eleven coins stolen by Thorned Namshiel at Demonreach and presumably given to Tessa.
 * Rosanna's unknown coin: Rosanna is the current host, and has been for a presumably lengthy span of time. She looks like a red-skinned, goat-hoofed demon with bat wings. She was formerly Sanya's lover and recruiter. She's Tessa's second in command.
 * Saluriel: It was hosted for several centuries by Quintus Cassius until Death Masks, when he surrendered his coin to the Knights. It has a snake motif.
 * "Shaggy Feathers": Its former host is unknown. It was shot by Kincaid while holding down Harry with "Obsidian Statue" at the aquarium—a two-in-one shot. It was one of the eleven coins stolen by Thorned Namshiel at Demonreach and presumably given to Tessa.
 * Tarsiel: Its former host is unknown. It either drowned, or was killed by Luccio, Michael, or Sanya at the aquarium. It was one of the eleven coins stolen by Thorned Namshiel at Demonreach and presumably given to Tessa.
 * Ursiel: It has a bear motiv and, since 1849, its host has been Rasmussen, and was defeated in Death Masks by the Knights of the Cross. His coin was held by the Church until sometime before Skin Game, when Nicodemus gave it to the Genoskwa. After Dresden killed its host in the Gate of Ice, the coin remained in Hades' Vault.
 * Urumviel: Its former host is unknown. It was deflected by Harry into an energy beam at the aquarium, but was among the eleven coins stolen by Thorned Namshiel at Demonreach and presumably given to Tessa. "He had a lot of muscle and a ridge of leathery plates running down his spine."
 * Varthiel: Its former host is unknown. It was defeated by Jared Kincaid at the aquarium. It was one of the eleven coins stolen by Thorned Namshiel at Demonreach and presumably given to Tessa.
 * Four unknown coins: Its former hosts are also unknown. One drowned, two were killed by Anastasia Luccio, and two were killed by Michael Carpenter and Sanya at the aquarium (Tarsiel is included in this). They were some of the eleven coins stolen by Thorned Namshiel at Demonreach and presumably given to Tessa.

The Denarians
Whoever has a coin can draw on the Fallen's power: use it to shapeshift, heal wounds and more. Many have been alive for a long time and some have developed talent for magic. Harry calls them certifiable nightmares. They are very hard to kill.

Their ability to shift into a form more suitable for fighting usually arms them with such weaponry as claws, fangs, horns, poisonous bites, hair that is razor-blade sharp, etc. Molly calls that ability "Battleshifting". Each Fallen has their own preferences that seem to adapt to the holder of the coin.

They have a cult of human goons with their tongues cut out. In addition, they have guard dog-like creatures that are ugly, fast, and have big teeth. What makes them the most dangerous is the Fallen themselves. They are older than time and have spent thousands of years learning the mortal world and the mortal mind. They understand things humans can't grasp. They know every trick and move. They are riding shotgun with each holder or in the driver's seat. They have a perfect memory and a vast library of information.

They were signatories to the Unseelie Accords until Small Favor when the Accords were violated by Nicodemus; he later mentions to Dresden that he's not a member of the Accords anymore. It is unknown whether this just applies to him or the entire order.