Black Lion is a manga series by Go Nagai that ran from 1976 to 1978, that also received an anime adaptation in 1992.
The OVA tells the story of Oda Nobunaga, a 16th-century warlord intent on conquering all of Japan. With the help of time-traveling aliens from the future, he is able to further his goals with Jinnai, an invincible cybernetic samurai who hates ninjas. With these unconventional allies, the victory of the warlord and his mechanized army seems all but assured.
Enter our young hero, Ninja Shishimaru, the sole survivor of a battle where his girlfriend and comrades are killed by Jinnai. The story follows his quest for revenge, as he faces hordes of mechanized enemies, evil samurai and aliens, with the help of a formerly hostile sect of fellow ninjas.
- Ax-Crazy: Nobunaga makes it clear to his subordinates he's only interested in war and death, even if it means that they die as well.
- Dare to Be Badass: Villainous version; Nobunaga (or rather, the alien possessing him) gives Jinnai a talk like this to encourage his Roaring Rampage of Revenge.
- Losing Your Head: One of Jinnai Douma's attacks have him detaching his head, which then flies all over the place while firing laser beams all over the place. It needs to be seen to be believed.
- No One Could Survive That!: Played practically to the point of parody, with the number of times the ninjas fail to kill Jinnai.
- Roaring Rampage of Revenge: Jinnai and his family were killed by ninjas; when he was brought back and made immortal, he wants to kill all ninjas.
- Cool vs. Awesome: Ninjas vs An Immortal Cyborg, rule of cool doesn't even begin to describe this anime.
- Stuff Blowing Up: At a certain point, the ninjas' strategy against Jinnai becomes "double the explosives we used last time, repeat as necessary".
- Schizo Tech: Aliens from the future have provided the Oda army with tanks, Powered Armor, heavy machineguns and laser weapons, in addition to the period-appropriate spears and swords.
- Teeth-Clenched Teamwork: The rival Kouga and Iga ninja clans are forced to work together to defeat Jinnai.
- Tempting Fate: One of the samurai in the opening scene claims that Nobunaga's matchlock riflemen won't be able to attack them in the rain. Cue Mecha-Mooks with machine guns.
- What Happened to the Mouse?: In the anime, things are left unresolved at the end. There was probably supposed to be a sequel, but there never was one. Things are actually resolved in the manga, but the anime only adapted less than half of the manga.