This is the one that makes you feel the floor drop out. After the Chaos war, Kojiro and Ryuma come home to a Fuuma clan eating itself alive, and the enemy is no longer a rival school's hired killers but the brothers who fought beside you. Masami Kurumada's fingerprints are all over it: the theatrical sword poses, the beautiful-doomed-boy designs, the belief that loyalty is worth more blood than any victory, which is exactly why betrayal from inside the clan hurts more here than anything the Yasha ever did. And it is one episode. One. The Hakuo Academy ninja war that started in Yasha-hen and escalated through Seiken Sensou-hen gets a single OVA to land its darkest turn, then the lights come up. If you grew up on early-90s OVAs that got cancelled mid-thought, you already know this particular ache.

The final chapter of the Fuuma no Kojirou OVA saga begins after the Chaos war. When Kojiro and Ryuma make their way back to earth, they find no peace waiting for them: members of their own Fuuma ninja clan are killing one another. Earlier entries saw Kojiro sent to Hakuo Gakuin to fight the Yasha clan, who served the rival school Seishikan. This single action episode turns the fighting inward, setting Fuuma against Fuuma.