I tried to replicate what you did with serveral variations but didn't managed to trigger the bug unfortunately.
From the crash report I know it has something to do with not able to load the character protrait in battle.
I also thought it would likely be related to the third skill but it dosen't do anything relating to protrait changing in kistune form.
The only forms it would affected would be Mouse, Rabbit, Fox and Golden Retreiver.
What do you eman by starnge behaviour?
Also did you had full support on?
I disabled it until I found and fixed the bug so no one else downlaods the versiona and may also encountering it.