Complex sentence: The green Ur-Quan now called themselves the Kzer-Za, after the scientist who had freed them; they followed the Path of Now and Forever, which called for the enslavement or imprisonment of all other sentient species.
Split into simpler sentences: The green Ur-Quan now called themselves Kzer-Za, after the scientist who effectively freed them. The Kzer-Za followed the Path of Now and Forever, which called for the enslavement or imprisonment of all other sentient species.