[He definitely hasn't heard anything about this. Akechi surely speaks from experience - has seen battle in a form that Eren didn't necessarily expect.

[It's exciting, to be learning this from him - not Maruki, who he expects to be forthcoming. His gaze sharpens on Akechi.]

It makes sense. If they come from the collective unconscious, then they would be of a common type, right?

Humanity's collective desires being disorted...That's pretty universal. I just wouldn't think of it manifesting that way...

[He can't help but relate it to a pure titan vs. a titan shifter - a shadow vs. a persona and the person its attached to. The commonalities are surprising...]

That would leave only the people with the strongest wills to fight, wouldn't it? That's pretty universal too.