So Garrett and Coulson both drew that mysterious diagram because both of them were injected with GH-325?
Well it appears to be Kree writing, so the assumption that the "Guest" alien had some kind of information encoded right into it's DNA. How that can transpose itself into a human brain to be expressed via wall scribblings...well it's comic book logic. Plus crazy wall scribblings is an old trope for indicating deep or "divine" knowledge...and for being crazy...
So what are we thinking about the multiple Koenigs? Clones? Life model decoys? Or just boring normal human twins?
Oh and Calling it right now: Fitz is going to become Modok.
