A pact can give a demon a temporary cover. In the book Demon: Interface, an example of a transferable pact is given:
Gaunt pays Yuri a visit and promises to save his business by improving Yuri’s skill and injecting cash, in exchange for borrowing it for a week at an unspecified future date. Gaunt makes it clear that it won’t be him taking the cab over himself.
Yuri: Asset (Resources 2) + 2, Asset (Professional Training: Cab Driver 4) +2
Gaunt: Duration (week) 0, Cover (Medial) 2, Transfer Pact 2
Onyx Path Publishing. Demon: Interface (Chronicles of Darkness)
During the period that a demon borrows Yuri's taxi business, I assume Yuri just loses that part of his reality, and the demon assumes it for the week. The text is unclear if Yuri gains resources permanently or not, but the demon only gets the cover for a week.
The practical effect I would like to create is a "temporary Soul Pact" in which the demon steps into the entire person (as in a Soul Pact) but only for a limited time. Of course, this isn't possible in a normal Soul Pact. Is there a way to do this within the rules now?
Why I want this: I would like to have a storyline where an agency gives a PC a temporary cover of a millionaire, "Bruce Stark," so that the PC can attend a mysterious auction. Stark has a pact with the agency for the wealth, but the agency has the right to "borrow" his reality for short times. This gives dramatic opportunities like those in spy films when a spy is disguised as someone famous and has to pull off the impersonation.