Woona using her underwater basket-weaving skills to trap a giant octopus, saving the Lunar Maria.
The escape from the Changeling hive, with Woona delivering an epic boop to the Changeling Regent and throwing an exploding baby roc in her face!
Woona activating her "pretty pony princess powers" while falling to her doom, safely flying herself and her friends to safety. (Granted, two of them could already fly unaided.)
Though most of it was ineffective, Woona's improvisation during the final battle is worth a mention, from folding her cap into a cannon and launching herself at Dark Woona to slipping into the water during her opponent's monologue and freeing herself from the evil jam that had trapped her. (And the latter trick does work!)
What does Woona do when the Elements initially fail to activate? Instead of sinking into another Heroic BSOD, she takes the Elements themselves and throws them at Dark Woona!