Crystal-Crested Buzzards Transform Burning Corpses

The circumstances may be different to a gestalt looking for a suitable host to possess, but I think it follows that they won't be interested because they find hot fires very uncomfortable or damaging to their power source.

On a related note, igniting and extinguishing corpses makes them instantly disappear to make this kind of counterplay available, though it is a lot less intuitive and possibly not intended.