'M.D. Geist' aka 'Sōkihei M.D. Geist' (1996) Dir. Koichi Ohata. 

Phook yaaasss!!!! Full on adrenalized mecha-mayhem wherein the singularly savage Most Dangerous Soldier Geist awakens in a gravely bellicose frame of mind, and proceeds to gruesomely annihilate everything in his steely-eyed sights!!! In this bleak, war-torn dystopia it's kill or be killed, might is always right, and to the mightier come the blood-spattered spoils! The very last of his unkind, highly trained, armour-plated super soldier Geist wages total war just for the sheer bloody hell of it! A refreshingly brutal protagonist, the psychotic M. D. Geist isn't so much an anti-hero as vehemently anti life itself! Some manga fans disdain its unleavened nihilism, while others relish it, but Ohata's ordinance overloaded, carnage crammed, End of Days, mind warpingly mental militaristic Manga is most certainly never dull!