Juubee Ninpuuchou, Jigen Sengokushi: Kuro no Shishi - Jinnai-hen Recommendations
Both are ninja anime from the 1990's that are set in feudal Japan. Both are action-packed anime with lots of violence and blood. Ninja Scroll has a better story, however they are both very entertaining to watch. If you enjoyed one, you will enjoy the other.
Ninja Scroll and Black Lion are very similar in both content and execution. Both are set in feudal Japan and feature ninja characters. Both anime are quite action-packed, with a lot of violence and gore, creating a similar tone and mood. Also, the abilities of the main villain in both anime are quite similar.