The Ultimate Showdown! Mega Evolution!!

Roy, Uruto and Friede duel against Sango, Onyx and Agate! But during this fierce see-saw battle of Mega Evolved Pokémon, Roy and the others spot the key to victory! What is it?! Meanwhile, Liko and the others meet up with Amethio before finally reaching the central parts of Rakua... where they spot...?!