It means someone that can go any way it wants to, like in Uno, a wild card can be any color.
These sound great, I can't wait to see the original leader, but one question makes me wonder... Has he evolved like other makuta... Or is he still biomechanical?
The Takanuva one is very cool, I bet people think Takanuva was killed by a door, and Makuta was revived.
Mutran's Story is going to be very nice, I wonder how far back it goes.