Nature Transformation apparently not working?

A Confused creature of mine cast Firestorm and due to confusion, cast it on my party. However, despite having a Nature Shapeshifter in the team, it still damaged the team.

I thought this was happening to me, but when I checked the battle history it was actually the heal triggering blight damage.

Did you check the history to see if it was actually the firestorm doing damage?

It happened again, and I can confirm no Blight whatsoever was in to play.

After a bit more of battling, I can confirm that Attacking does work and heal as normal, but spells (or at least Firestorm) don’t undergo the same effect and still damage your party.