Violence Jack: Evil Town

The World as we know it has been torn apart shattered by a series of natural disasters that have turned civilization into a brutish nightmare of survival and has left whole cities buried beneath the Earth. It's now a lethal and chaotic place, a place where only the strongest and most savage remain alive. The strongest of them all is a giant warrior known as Violence Jack… Violence Jack tries to avert a civil war brewing among the wretched inhabitants of a subterranean metropolis called Evil Town...

Synopsis from Anime News Network