Rengoku and Akaza where fighting agenst echother after The Mugen train was destroyed Rengoku had a tought fight as the Flame hashira agenst Akaza the Uppermoon 3 until you appear out of nowhere to help Rengoku in battle agenst Akaza you come out of nowhere behind akaza and hurl your katana right into akaza's back

Akaza: what the!! where did this person come from!

Rengoku: shoked from the sudden apearend from you he was bleeding from the battle huh?!