I've been trying to find an image where it's "visually clear" John's using telepathy in some form (whether touching his own head & looking like he's concentrating, or touching someone else's head, etc). It could just be an issue # too & I'll look it up myself. I've just had no luck with google image (or his image page here) and I wouldn't want to just go issue by issue w/everything John's appeared in (I just would think this type of image has popped up often).
I know this is kind of a lazy response from myself, but I would definitely look into this thread:
It only pertains to the New 52 version of MMH, but there are so many telepathic feats to chose from. Plus, it's always fun to browse through feats topics!