最強メガバトル！ゲッコウガVSメガリザードン！

Ash and Sawyer meet up for a battle, and Greninja and Sceptile, now evolved, are excited for their rematch! Nearby, Alain, who’s on a journey to study Mega Evolution, pauses to watch the battle, and he’s very intrigued when Greninja seems to transform just before defeating Sceptile.
Alain wants to see more of what Ash’s Greninja can do, so he challenges it to a battle against his Charizard—and when Charizard Mega Evolves and Greninja’s appearance changes again, the battle becomes intense! Greninja is ultimately defeated, but everyone is eager to learn more about this mysterious transformation!
Meanwhile, Team Flare’s experiments seem to have reached a breakthrough...

Next episode

S17E13 - サトシとセレナ！ダンスパーティでゲットだぜ！！