OBSCURE O.V.A.S, *Black Lion

Go Nagai created this manga series in 1978 titled Kuro no Shishi which was turned into a 1992 OVA one-shot that was rebranded in English as Black Lion. This is one of Nagai's few historical fiction pieces as it fuses Terminator with Ninja Scroll. The creator of Getter Robo would later go on to make such bombastic titles such as Devilman and Violence Jack with similar vibe of hyper violence and bloody gore.

In 1580 Japan, the samurai lord Nobunaga Oda plans to take over the countryside, and he recruits the burly Ginnai Doma to be part of his campaign. This version of Nobunaga isn't what you've seen in several other anime, because here he appears to be an alien taking on the human form of the feudal lord that has transformed Ginnai into an immortal cyborg who takes everything the rival ninja clans can throw at him. From being stabbed, set on fire, blown up, and having his head lobbed off, Ginnai is invulnerable to all conventional attacks of the time. The key element to this is time itself as the aliens are time travelers who are trying to change history against a force of temporal protectors, better referred to here as the Black Lion. The Iga and Koga clans put aside their differences to combine forces to finally destroy Ginnai, but the vengeance crazed Shishimaru care only for avenging the death of his fellow ninja. The united clans go on a harrowing suicide mission to terminate this Terminator once and for all with no knowledge of Ginnai's high tech backers.

Black Lion is a bare-bones grindhouse anime in the most extreme way possible. There's a paper-thin plot leaving entire deserts full of contradictions. The major fault is not having the original source material handy as the manga has never been put out in English. ADV Films released it on dubbed/subtitled VHS and DVD, but it is not available on streaming or Blu-ray, making this a rare find by modern methods. It's not the greatest example of Go Nagai's works but should entertain you for a night spent with your drinking buddies.