If a spirit has the power of Possession, when it assumes control of a host body, are its other powers (for example: Immunity, Magic Sense, Search, Guard, etc.) conferred to the "shell" body? In other words, if a spirit with Magic Sense takes possession of me, can it use that power while in control of my body?

Yes, anything not physical (like venomous spit) can be passed onto the target.

Sphynx

Thanks.