M.D. Geist (装鬼兵MDガイスト "Sokihei M.D. Gaisuto", literally "Demon-Garbed Soldier M.D. Geist") is a 1986 40-minute post-apocalyptic science fiction OVA directed by Koichi Ohata. Famous for its powerful soundtrack, over the top action and violence, intricate mechanical design by Ohata, multiple animation errors and bizarre story, M.D. Geist is generally seen as a bad production, but has also become somewhat of a cult classic.
In the future, the war-torn planet of Jerra has been locked in a war between the Earth government loyalists and the Nexrum corporation for decades. To counter Nexrum's advanced weapons, the Earth government developed one-man armies, the Most Dangerous Soldiers. However they proved to be far too strong, and most eventually lost their minds and went on rampage. Being one of the surviving Most Dangerous Soldiers, MDS-02 GEIST was put into stasis inside a satellite in Jerra's orbit. Years later, the satellite prison crashes on the desolate planet and Geist reawakens. He recovers a Powered Suit, battles with bandits and units of the Nexrum military and eventually joins a group of Earth army commandos in a mission to deactivate the secret doomsday weapon on Jerra: a self-replicating robot swarm known as "Death Force". However, there's more than meets the eye to Geist.
A sequel OVA, "M.D. Geist II: Death Force", has been made a decade later, alongside a comic book prequel. The 1986 OVA has also received a Director's Cut edition, which fixes the animation errors, adds more blood and some new footage.