This is an attempt at a Dresden Files conversion. Feel free to use in your game.
The blackened denari are the 30 silver coins paid to Judas for betraying Jesus. Each one contains the essence of a fallen angel.
Each coin appears to be a small silver coin that has been blackened as if subjected to fire. The design on the coin is the name of the Fallen Angel in celestial.
The coins are intelligent artefacts with an Ego score of 30 and Intelligence, Wisdom, and Charisma scores of 18.
Wilfully touching the coin with bare skin is enough to have the image of the fallen angel appear in the mind of those who touched it. Accidental or forced contact with the coin does not count, the victim must touch it of his own accord. The shadow of the fallen angel will appear as an attractive member of the same race as the victim as if Major Image or Dream had been cast on him (DC 30 for both). Only the one affected can perceive the image. It will urge the victim to pick up the coin and offer help and advice. It has 10 ranks in Knowledge (Arcana, Nature, Planes, and Religion) and 5 ranks in all other Knowledge skills. It cast the following spells 3 times a day on the victim with his consent: Identify, Cure Light Wounds, Cure Moderate Wounds, Bull's Strength, Bear's Endurance, Cat's Grace, and Tongues. It will also aid the victim by granting him a free Metamagic or Combat feat for the day most likely to assist him (GM's choice). Each time the victim agrees to receive aid from the fallen shadow, it can also cast Suggestion on him. The Suggestion will either be to pick up the coin or to distance himself from family and friends who can help him be rid of it. The shadow can Teleport the coin to the victim if he agrees to accept it.
The shadow can be gotten rid of only by the consent of the victim and a Remove Curse against DC 30. Also, any spell or supernatural attack against the victim with the pain or mind affecting descriptor that does at least 50 points of damage has a 5% chance of removing the fallen shadow as well.
If the victim ever agrees to accept the coin, he also gains the following benefits in addition to the shadow's abilities:
* Ageless -- Client remains permanently as an adult and no longer suffers penalty for aging. Bonuses still accrue, however.
* Cast Heal on self only once a day.
* Battle Form -- The wielder of the coin gains a number of Synthesist Summoner levels equal to his character level. The Eidolon form will always have two pairs of eyes, one for the wielders, and one for the fallen inside.
The Coins are Chaotic Evil with a purpose of Slay/Defeat All. If the wielder wins an ego contest against the coin, he can choose to cast it aside and lose all abilities of the coin and the shadow.
like, dotting for reference
I haven't got around to reading the Dresden Files series yet but from what I've heard, I think there is a holy order dedicated to combating the coins. Is there a way to destroy them? They're artifacts, so it should be difficult but I thought there was a way.
You seem to suggest that the coin only uses Suggestion to make sure it stays with its victim. I would think that it would also use it to slowly influence its bearer towards evil.
There is a Holy Order dedicated to fighting the coins, but as far as I remember there's no way to destroy the coins, they can only lock them away and hope Nicodemus doesn't find them.
You might consider a different form of influence for the coins influence. For instance using points for each time the character gets help from the coin. Set different values, probably starting out high and lowering with each new step achieved to represent the spiral downwards becoming faster. You also might want to consider giving the character the Breadth of Knowledge feat from the APG. Also I believe Identify doesn't exist anymore as it is a function of Spellcraft or Kn: Arcana.
I would suggest different Alignments based on the Fallen. Lashiel would be an example of NE, Nichodemus and Deidra of LE, and Tessa and Rossana of CE.
You might also wish to consider making Denarians like Ursiel and Magog more like Vampire Spawn as their hosts are chosen because they are weak and can be enslaved. Admittedly more powerful than Vampire Spawn, but I think their is more commonality than with someone with 5+ class levels.
To answer answer OldManAlexi's question, the Knights of the Cross's mission is to redeem those who have been taken by the Fallen. They aren't there to kill them and have done with it.
Honestly just reskin the Synthesist, at most change out parts of the spell list. Other than Nicodemus (who is really just a normal summoner with a nifty necktie) this can be used to represent all of them shown in the books so far. Not to mention the fact that this leaves them in the realm of potential PCs.