Agnes.... Agness.... Agathaness.... AgathaHarkness
Goddamnit, it was right in front of our very eyes this entire time!!
Agatha still opens the doors for many of our theories - Fantastic Four, Mephisto, etc - but I'll be severely disappointed if this turns out to have nothing to do with Mutants it was a fun pop for the audience I guess, but damn I'll be supersad if that's all it was.