By any chance is the mirror man in the game meant to be the same mirror man from the theory the mirror man is Eren. I mean the way he acts definitely supports it as we learn in the last episode he was a downbad mf with some time issues. The mirror man speciffically wanted Mikasas panties in arc 1 and he also acts like Eren in the later arcs. I am calling it rn before anyone else and will be sad if I am wrong.