Does the “rider” get the movement abilities of the host? What about special senses?
Standard movement and abilities are included in the “owner’s manual” that comes with the host. The possessors’ tie with the Symphony provides such instincts for free. Learned skills, such as a pigeon who’s been taught to do loop-de-loops when it wants birdseed, are unavailable. Senses are included with the vessel unless, for some reason, they depend on a learned skill. So, in a cat body, for example, the possessor would get a bonus to sneak (due to the small size and padded paws) and a bonus to climb trees (claws), but a GM might rule that when walking across a narrow ledge, no roll was necessary since that was included as part of a cat’s “natural movement” abilities.