So Uira is a spirit... makes sense, we don't know everything about the magic in this series but it felt to me that transfigurating a human into another being may not be achievable.
I understand her anger in this case, but she is turning things much worse, the masked creeps may be the cause but it seems they didn't want to cause destruction with the spirit, even if there is panic and that isn't exactly much better.
But now that Uira has done that, things are about to escalate quickly.
Curious about what type of spirit she is too, her form is really "fancy" to be a simple one, the clearly dragon tail coming from her head (amazing design choice IMO) tells me that she may be a spirit of storms, as the eastern dragons are connected to it.