Fanwalker Friday time!
Saint Rosa of the West Rosa was once the greatest healer on all of Innistrad, people traveling far to the abbey she stayed at. Rosa never believed in material things, so she never once took payments for her expertise which caused her to have some resentment from other clergymen who had lesser knowledge but took money for their services. In total, Rosa completely wiped out three deadly plagues with her medicine.
One day though she returned home to see her abbey and fellow worshippers of Avacyn ablaze with devils cackling around it. She felt a sharp stab in her back, and before she knew it she woke up as a spirit on the plane of Ravnica.
Some say that the reason why she became a planeswalking spirit, only being visable to other Planeswalkers ( but making up for it by possessing other beings to anchor herself to a plane) is because she saved so many people in her life that Death itself resented her so much that she got stuck in between. Rosa loves making bad jokes and it was usually the only downside to her treatments, having to hear them.