In the first chapter, you have an itty-bitty blind girl, a teenage boy, and two women against a ha'tak full of Jaffa. Managing to escape seems impossible, right? Well, they still do.
Sergeant Heather Dyne jumps on the yukioso with nothing else than a knife covered in olive oil and salt. She's acting on a hunch, she gets her arm flash-iced over for her efforts, but it works!
When he realizes how bad her shape is, Zuko decides to help by defrosting her arm. He ends up creating fire-healing on the fly by using another way to bend lightning.
Janet banishing the yukiuso in Chapter 8
"This," she spat, "is an infirmary. Dohman and Gabor are dead and beyond my help, and I certainly don't have a prescription for you." Her voice tightened into a whipcrack. "So you can consider yourself discharged with prejudice!"
It wasn't her imagination. The line of salt Toph had laid around the edge of the infirmary flared, bright as the candles still flickering throughout the room. She had a strange sense of pushing…
And the yukiuso was gone.
Chapter 11: Aang is battling a face-stealer-class ice spirit above an alien world. Katara is in an airborne spaceship on the fringes of same and decides Aang could use backup and/or a Cooldown Hug.
O'Neill: "... If you think I'm letting you walk out into the middle of that...."
Katara: "I don't recall asking permission." (opens hatch and gets blasted into the snow-filled sky)
A few paragraphs later:
Narrator: This was a place of snow and ice and polar night; the yukiuso’s home ground. But she was a master waterbender of the Southern Water Tribe. Of all of them… she was the only one other than the Avatar who could go toe to toe against this thing and survive.
Katara:Because this is my ground, too…
Narrator: She swept her arms around. Snow whispered to water and cracked to ice, and her ice-igloo was suddenly a sheltered passage into the cold fury of the storm. Snow and wind and flashes of spectral blue that she knew better than to stare too long at battered at the ice. Furious. Impotent. Her lips curved in a fierce grin.
Katara:And you can’t freeze ice, spirit!
Also? Face-stealer-class ice spirit the size of a goddamn thunderstorm versus the Avatar Spirit. How cool is that? And said ice spirit was actually winning.