I want the spirit to function as a kolyarut to enforce a contract since I don't have entropy 5 there is always homebrew but I want to know if one already exists
2 Answers
It may not have the exact details you want, but there is an option suggested by Vampire: the Masquerade. The level 5 Thaumaturgy ritual Blood Contract has an effect like you describe, and implies that demons can be associated with compliance:
Blood Contract
This ritual creates an unbreakable agreement between the two parties who sign it. The contract must be written in the caster’s blood and signed in the blood of whoever applies their name to the document. This ritual takes three nights to enact fully, after which both parties are compelled to fulfill the terms of the contract.
System: This ritual is best handled by the Storyteller, who may bring those who sign the blood contract into compliance by whatever means necessary (it is not unknown for demons to materialize and enforce adherence to certain blood contracts). [...] (V20 Core Rulebook, page 239)
The details are left undefined, but that the ritual describes demons appearing to enforce contracts sometimes (meaning not all the time) indicates that the magic surrounding the contracts themselves is not necessarily enough to ensure compliance. This in turn suggests that at least some demons have some association with keeping or enforcing contracts, at least in some cases. It's not much of a stretch to go from a contract to an oath.
This doesn't answer how a character would go about contacting or getting such a creature to enforce a contract (outside of this particular ritual, which will not be directly available to a mage), but it is at least an option with some representation in the published books.
You can use a Spirit tasked with enforcing a contract or punishing things. The best inspiration here would be a Garou Fetish:
Questing Collars1
The Garou know a rather nasty fetish in the shape of the Questing Collar. As a Fetish, it is powered by a spirit. If the Fetish is activated, a timer starts to tick and if it is not concluded by the time the timer is over, the item breaks, and the angry spirit goes to enact an act of punishment.
To make one, a heavy iron collar is bound with any spirit with the capacity to kill large numbers of people if need be. 1
Once the time frame is up, the collar shatters and the spirit within is released. The spirit within will then move to kill those closest to the wearer: family, mates, children, and so on.2
"Any spirit that can kill large numbers of people if need be" is rather wide, but it could be a predator spirit, a spirit of death or even a bane. A Bioweapon Bane,3 Stood Ground,4, Nexus Crawlers, 5 Scrags,6, Hunter Spiders,7 Twister and Vortex8 come to mind, but there are many more options, like, you can just build one!
Example Enforcement Spirit
One example of a spirit set up specifically to serve as a spirit in such a collar would be my interpretation of a "Rambo":
Rambo (Wyld Jaggling of Revenge)
Rage 10, Gnosis 5, Willpower 8 ; Essence 23
Charms: Re-Form, Tracking, Materialize (8 health levels), Choose two of: Blast, Create Fires, Shatter Glass, Short Out
Image: A soldier of undeterminable skin coloration, covered in dirt and facepaint, hunting for those who wronged him. The smell of coprecipitated aluminium salts of naphthenic acid and palmitic acid and jungle mud are the first sign that Rambo is near, but once he goes into action this changes to the scent of napalm and burning flesh.
Background: Born from the desire of Veterans for revenge on those who killed their units just as much as the demand for proper treatment by the civilians back home, Rambo is just the latest form of these spirits. Some of these go back to the legions lost in the Teutoburg Forest, while the largest batches are the result of the World Wars and the many conflicts thereafter. A Rambo is in essence a power of Wyld, demanding change.
1 - Hammer & Klaive, p.79.
2 - Hammer & Klaive, p.80.
3 - W20 Umbra The Velvet Shadow, p.121.
4 - W20 Umbra The Velvet Shadow, p.138.
5 - W20 Core, p.444.
6 - W20 Core, p.446.
7 - W20 Core, p.449.
8 - W20 Core, p.452.