You know how it was confirmed that Joan of the Ark was a previous Miraculous holder? I did some research on her of my own, and I read this one article where it mentioned her "hearing voices"and being accused of Witchcraft. She was killed for those very reasons along with dressing like a man. That made me realize something pretty sad.
What if in the Miraculous universe, those "voices" she was hearing was really Tikki and she just acted like she was a schizophrenic to protect Tikki? What if she pretended to hear voices that weren't really there to help protect Tikki from everyone and keep the Kwamis a secret?
I read something else that said "...she also claimed to see various Saints such as St. Catherine and St. Margret..."
I looked up information on both of them and St. Catherine sounds like she could have been a Ladybug. St. Margret on the other hand, I was unable to find anything on her that made me believe that she could have been a previous Ladybug. If she was in the Miraculous universe, she must have done a really good job hiding it.
I wanted to look them up because I believe that there's a possibility that Joan of the Ark might have just been seeing the spirits of he previous Ladybug Miraculous wielders. This could be possible because what if a bit of a previous wielder's spirit stays in the Miraculous to give the current wielder help when they need it.
She was accused of hearing voices. Kwamis try to keep their existence a secret from non-miraculous wielders so Joan of the Arc could have just said that to protect Tikki.
She was accused of Witchcraft. Witchcraft=Magic, Magic=Luck Charm/Miraculous Cure.
She saw people who were already dead. The previous Ladybugs.
She "dressed like a man". The Ladybug suit could have looked that way because of how females were treated back in the 1400's.
In the Miraculous universe, Joan of the Arc wasn't executed because she was mentally insane, it was because she was a Miraculous holder. I know that this is pretty dark for a cartoon, especially one meant for kids, but if you don't believe me you can look it up for yourself.