The Mundus Stones are just like the Standing Stones from Skyrim. They are based on the birth signs/constellations, they add abilities, and you can only have one in effect at a time. They’re prettier than Skyrim’s stones, though.

Collaboration with the hubby.
Photomanipulation by me.
Screenshots © 2014 Zenimax Online Studios.
Card created at www.mtgcardsmith.com