Tonton Streaming ThunderCats (1985) S1E27 - The Thunder-Cutter

Mumm-Ra summons the great samurai Hachiman to seek and destroy Lion-O. He tells Hachiman that Lion-O and the Thundercats are destroying his planet. Hachiman and Lion-O confront each other, but their swords refuse to draw on each other. They become allies and hope to destroy Mumm-Ra together. Enraged, Mumm-Ra summons another warrior, a ninja, to sabotage the Thundercats, and retrieve Slithe, whom they have captured.