Nostradamus is a character in the Medieverse who takes a minor role in the story.
Someone who seems to have known about the plague for a long time. While he is not actively looking for a way to stop, he tries to prevent people from dying from it. He took home somewhere in Meridian, although he is quite hard to find, and usually only opens his home up to those who are near death if they even manage to make it. He suddenly appeared at the monastery of Septent one time where he trained Leah in medicine for a few years before disappearing suddenly, leaving his fate unknown.
He is often called the man who doesn't talk. Some say he is a mute, but in reality Nostradamus prefers not to talk. He tries to hide any expressions by always wearing his plague mask, and also to not catch the plague himself. In reality he can talk but limits it to only whispering to people. He always seems to be calm in situations, and even looks like he acts indifferent to the plague and the people dying from it, despite him trying to keep them alive.
Being the most notorious plague doctor around, he certainly is specialized in medicine. His talent in this is so good that he can cure people who are on the brink of death, or at least extend their time on Earth by curing the most major issues. Is tranquility is something of an ability as well, as no one seems to stay so indifferent in dire situations.