Really I never even tried to go into the science  of how it works, since we're dealing with magic. Some one can argue that magic that summons fire would be immune since the fire is not magic, same with lightening or any spell really that involves conjuration or evocation. Same thing happened last match involving that whole heat sun thing, since magic did not sustain it but did summon it. So it was magic but not magic, so at that point you probably need to agree or a ruling. 

So no on the charades?