Shion transforming into a One-Winged Angel form after seeing a light within Moryo's darkness, which was her Mother's light. Shion combined with that power in a dazzling display that nearly takes Moryo out. Sure it was a vision, but it was still awesome.
Shion: You and I will disappear, together!
Naruto and Shion's "Super Rainbow Rasengan", which not only kills Moryo, but also destroys his lair and causes a dormant volcano to erupt.
Naruto's motivating speech to get Shion to help him create the particular Rasengan.
Naruto: Can you see?! Can you hear?! What is your heart telling you? Do you want to die like this or what? Do you want to just fade away?!
Naruto: I can't hear you! Say it Shion! Say it in your own words! Come on, let me hear it!