Where is all this heat going? It's reasonably intuitive that Kiri would be able to generate heat out of nothing but deleting it is kind of weird, now she thinks of it.

But nothing's getting warmer.

And the only thing around that can't get warmer is her.

...Kiri goes up in a column of flame, feeding it on what she's drawing off Melian, and has enough attention to spare to keep her clothes from igniting.

Are you all right?

Yeah, I'm fine, just seeing if it helps.

It helps. Colder, colder, colder, nothing-moves colder...

...and now Kiri can't go any colder. She burns, focusing - You okay?

I cannot move. This form seems stuck, there's no avenue to exert force on it. That could do a great deal, in the war, though we aren't our forms and destroying our forms doesn't suffice to destroy us - I can still work some magic from here but probably not enough to affect a battle or, more relevantly, to do you harm. 

Good to know. I'll back off now and see what happens - should I step you back up or jump you to your former temperature or just stop affecting you?

If you stop affecting me I think I can restore it. If not, I'll ask you for assistance. 

So Kiri puts herself out and stops concentrating on chilling Melian.

And some odd spark-like things float in the air around her, and then currents sweep them towards her, and then she's very slowly back in motion. So it seems that constraining us that way requires your continued concentration. Someone could shatter the form while it's frozen, though. 

What would that do?

I wouldn't be able to retrieve it, and I'd be damaged. I'd be more damaged, and its loss more significant, if it were one I was attached to rather than one I'd created for this purpose. 

Okay. Let me know when I should try heat.

You're welcome to help me get warmed up to normal faster. It may otherwise take a while. 

How fast?

I don't think this form will suffer much damage from being rapidly heated, it's not very complicated. 

Okay. So now she's ambient temperature.

Wow.

Okay, let us attempt heat. 

Up she goes. Kiri does not freeze herself - might make it hard to breathe if the air slowed too much. Hotter hotter hotter.

The physical form starts glowing. 

That's promising. Maybe.

There is not in principle an upper bound on heat like there is on cold. If you were capable of heating atoms enough they fell apart that'd be worrying and I'll stop you before you get that hot. 

Okay. I won't speed up suddenly or anything.

You are very far from the heat where that'd be relevant. 

I won't be able to pull the same trick in reverse, because while I don't need to be warm I do need to breathe.