Demon City Hunter (1986)

Blurb:
God’s come down to earth and all hell is breaking loose! Enter a world where demons seen only in dreams are real, oceans swallow cities, and the powers of the mind are preferable to guns. It is here in the "Demon City" that Kyoya Izayoi, master of the rare martial art of nenpo, wields the mythical sword Ashura in defense of beautiful Sayaka Katagiri. As the evil Dark Order and the Super Soldiers of the Special Abilities Task Force clash in a race to find the one believed to be God, Kyoya saves a member of the SATF - and lands himself smack in the middle of a mess. Meanwhile, members of the Dark Order ambush Sayaka. Can Kyoya slay the beasts and save the girl? Will Kyoya help the SATF defeat the Dark Order and their plan to destroy the world? It’s nature versus the supernatural!

Source: www.anisearch.com/manga/283