Doom for everyone. Didn't seem very diplomatic, from where Emily was hovering, so she finished up her spell. Then, she squealed softly as the Kitsune tail popped out of her skirt. After a few experimental swishes, Emily smiled to herself. It would make for a very nice addition.
'And, can shoot fire' The Kitsune put in, mentally grinning.
'I am aware of that. Fox Fire is pretty dangerous without...this. So, I dread to think what is going to happen' Emily replied. Not actually dreading it, but just saying it for the effect. 

Once her spell was finished, she brought the tail forward, and held the pure white flame to the tip of it. Instead of doing what Emily expected and setting the tail on fire, the flame slowly dwindled, and the tail end turned lighter in colour, until it was pure white.
'So, you know what to do right? It's not like normal magic, this is Sonnetical' The Kitsune informed Emily, who nodded.
'I got it, don't worry' She replied, before pointing the tip of the tail at the Demon, currently bearing down on Torrens. "Ten no kitsune!" she shouted, and then hovered amazed as a pure white line of liquid fire burst from the tail, smashing into the Demon almost at the same instant as she had shouted, a few seconds before Torrens seemed to fire his own flame into the Demon's eyes. The thing looked tough, but what Emily had just shot off would cause lava to boil in a heartbeat, so flame immunity would not help it very much with this special little trick.