Medieval Character #4 - Theodora & The Philosopher Stone

Imagine time travel to the middle ages was possible from the modern era. How would that reality effect the people of both modern day and medieval times? The challenge was to design 8 character (4 modern, 4 medieval) who have been effected by this time travel in some way.
This was the premise of the Artstation challenge, Medieval Back and Forth: https://www.artstation.com/challenges/medieval-back-and-forth/categories/169/submissions/73590