I don't think Krall was implemented well, I liked the concept of him, It's not anything new....even Star Trek has explored the very same concept and done it better....I can't remember the name of that next gen episode, but it was about this alien race that had recently fought a war using super soldiers, then had them locked up on a moon or something because they wouldn't fit in with the new peaceful society, the enterprise arrives, the soldiers bust out of jail, and havoc ensues, with the Enterprise being caught in the middle, (and a bunch of people gunned down if I'm not mistaken).....I haven't seen that one since the early 90's. but it was a pretty interesting ep. I think Krall would have been more interesting if he had still looked human...and not only that but he was recognized and remembered as a Hero by Kirk and Crew(and the whole of the same Federation he hated)...."But I read about your Missions in the Academy! You wrote the book on "X"! It could have been REALLY interesting if half of the film had consisted of Flashback sequences, Detailing Kralls (Who never adopts the name "Krall" and uses his real name instead) Crashing on the planet, grappling with his own psyche.....Coming to the conclusion that Humantity has moved on without him....therefore he is no longer human....and renouncing the federation....Have a power struggle between the "old " breed and the "new" breed in his crew....show him discovering the Swarm/Life draining Tech in the film.......you could still have the "present" of the film focus on the Enterprise and Jayla....but it would jump back and forth....as Kirk and co start piecing together "WTF happened here?" on the planet.....just my suggestion. In short, I think Krall had the potential to be an Amazing Star Trek villain that could have been very compelling...easily the best out of the 3 J.J. films....ut it just wasn't fully realized.....I loved Jayla Though.