Cometeers

In the second book in the Legion of Space series, Jay Kalam, Hal Samdu and Giles Habibula fight The Cometeers, an alien race of energy beings controlling a "comet" which is really a giant force field containing a swarm of planets populated by their slaves. The slave races are of flesh and blood, but none are remotely similar to humans. The Cometeers cannot be destroyed by AKKA, as they are incorpo...