User blog comment:NickFusi0n/A Theory on The Coordinate and The Wall Titans/@comment-93.209.16.74-20140525064024/@comment-93.209.3.106-20140525071323

Forgot something, and it's important. The Titan shifters used to make the walls lack skin. Eren's and Ymir's Titan forms have skin. The only shifters without skin are Berthold, Reiner and Annie. There seems to be a connection. Maybe the shifters within the walls are from the same homeland like Berthold, Reiner and Annie, and their mission is to liberate their "compatriots"? I mean, the wall Titans also seem to have Annie's "harden" ability.