Warriors Of The Storm

Description for WARRIORS OF THE STORM by Jack L Chalker:

GUARDIAN DEVIL

For centuries, Master System ruled mankind unchallenged. Then a small band of renegades commandeered the spaceship Thunder and fled into pirate territory. Now they were prepared to seize the five coded rings that together could shut down Master System--and return human destiny to human control.

With them went the one variable that didn't figure in Master System's equations: Vulture, a shapechanger capable of absorbing the body and memories of any other organic being. Without the information Vulture could collect, the rebels could never infiltrate the worlds where the rings were hidden.

Each ring was better protected than the last. And as each ring drew the band further into Master System's web, Vulture became aware of a possibly more insidious danger. An unknown entity with the power to elude Master System seemed to be giving the rebels an unseen hand. But the question was--whose side was it on?...

Book Three of The Rings of the Master.