Board Thread:Theories/@comment-33543289-20180703025502/@comment-33543289-20180704235126

Annie could very well be an illegitimate child like Historia was. As for the Braun serum. Maybe one of Reiner's relatives was a possesser of the Armored Titan at one point. But i see what you mean. As for the Attack Titan's hardening ability, maybe it has the ability to adapt if given the right 'tools' so to speak.