So during my game one of my players suggested putting Demonic Co-Pilot on an NPC because it would fit the character concept well. I'd never really looked at the ability before, but now that I have I feel it could be so much more than it is. DCP is based on the Denarians, which I feel encompasses a whole lot more than just transformation, so I've added a few things to make this more accurate. I've also had a look at the custom powers thread but I don't think that version works particularly well. So here is my attempt.
Demonic Co-Pilot [-VARIES]
Description: You have a spiritual parasite living in your mind, bringing its baggage along with it. This may come with a variety of benefits, but always comes at a cost.
Musts: You must have an Aspect reflecting this Power. You must take at least one ability linked to this Power. You may not take this power more than once.
Skills Affected: Many.
Effects:
Arcane Advisor: The spirit living in your mind has a lifespan measured in centuries rather than decades, and has gathered a wealth of knowledge and experience over the course its lifetime. This allows it to act as a workspace (as detailed on YS140). You may ask the entity questions up to Superb rating for the cost of 1 point of Sponsor Debt.
Sponsored Powers: On top of the knowledge the spirit possesses, it may also choose to grant you access to a variety of powers within its purview. Choose which powers you wish to take from the Creature Features, Minor Abilities, Nevernever Powers, Psychic Abilities, some Shapeshifting abilities, Speed, Strength, Recovery, and Toughness categories. Sponsored Magic is also available, though regular spellcasting powers are not.
Sponsor Debt: Many aspects of this power work hand in hand with the Sponsor Debt mechanic (YS289). If Sponsored Magic is taken as a Power, the Sponsor Debt mechanic is merged with this Power.
The First Taste is Free: Some spirits may be willing to give access to a single power without attached Sponsor Debt as a way of gaining the person's trust and/or reliance. As seen in the DEAD BEAT casefile, use of this 'free' power may come with other consequences such as allowing communication between spirit and host.
The Price of Power: Every time you use a power linked to Demonic Co-Pilot, the spirit accrues 1 point of Sponsor Debt, which may then be exchanged for compels on a 1:1 basis according to the spirit's agenda. The spirit is also able to deny use of any power, should it wish to.
The Struggle for Control: If the spirit so chooses, it may exchange any Sponsor Debt it has stored for a mental attack (defend with Discipline) with a strength equal to the number of Debt Points exchanged. If the character is Taken Out by this attack, he becomes permanently possessed by the spirit.
I've designed this power to be a double edged sword in a big way. It has access to the majority of powers, though I would leave it up to the GM's decision as to which powers a given spirit would be able to impart. Arcane Advisor is the greater of the two benefits it has, in my opinion, since it is essentially a portable superb workspace, which makes for a very broad spectrum of possible declarations.
I wanted to work in Item of Power somewhere as a way to tie this in to the Denarians more, but then I figured it would work the opposite way around. Take Item of Power with Demonic Co-Pilot as one of the imparted abilities.
The First Taste is Free is meant to portray the slippery slope. Get the victim used to your power, so you can deny it later or lead it further down the slippery slope. In Harry's case this would have been portrayed with hellfire, which Lash then used via compels to make Harry angrier, which could then be used to later make him break a Law. Slippery slope.
The Price of Power and the Struggle for Control are two sides of the same coin, really. I like the idea of the spirit being able to decide between short term goals, such as throwing the character into situations where they may need to buy more powers (or temporary powers), or long term ones that would allow it possession over the character. This would be especially good for characters that are used over multiple campaigns or over one long campaign as the spirit would be able to acquire a
lot of Sponsor Debt over that time. Could lead to some interesting situations where the PC is unwilling to rely on the powers he's grown accustomed to using, while frantically searching for a way to get rid of the spirit in some way.
So what do you guys think?