Mutant War (1988)

Earth... a nice place to breed. But you wouldn't want to live there.

The sequel to 'Galaxy Destroyer' which finds our hero Harry Trent wandering Earth's post-apocalyptic landscape full of mutants, monsters, and fragmented human tribes. Harry's attempt to help a young girl rescue her sisters, leads him to a group of armed mutants led by a human madman attempting to breed them and take over the world.