Akki News reports that episode 28 will be called ”The Betrayal of Zangetsu” (裏切りの斬月 / Uragiri no Zangetsu). Either this or the episode after it will feature Pierre-Alfonso in the arms of Zangetsu-Shin and the long awaited transformation for Kamen Rider Duke.
It’s hard to say since there’s a very broken translation, but the blog seems to also say that Mitsuzane will become Zangetsu in some way.
THEN WHO WAS GRAPE
I wonder if Mitsuzane will be getting a Genesis Driver like Kaito? Maybe Takatora’s own?