I actually wanted him to become a regular cast, he would make a good commanding officer and even an able combatant if the situation calls for it.
It's nice to see him back, but kinda sad that this scene basically says "okay guys this is the last time we'll see of the Osakan, just a closure that he bought the party a ship and you won't be seeing him do anything significant in the story ever again", so much for the only other guy in the entire anime apart from Ryuko who dares backtalked Satsuki while having a sword shoved into his face.