How about a movie that revolves around Ash and someone sent to replace Ash fighting over control of the Protagonist Chair?
"I am Shadow Ash. The will of the Pokemon fanbase has spawned me to answer the prayers of the people. Ash Ketchum, you are no longer fit to wield the Sword of the Protagonist. Forthwith, I shall checkmate you in a Pokemon Battle and claim what is rightfully mine: the title of protagonist!"