My guess is that Carol Marcus (Eve) will be an important character to discover the weakness of Harrison.
In the scene where McCoy is examining Harrison, Carol is nearby, watching him.
Perhaps she demonstrates strong personality and a lot of intelligence and Kirk will fall for her.
Maybe she's part of the group that augmented Harrison. Or awoke Khan from hibernation for Starfleet service and screwed him over.
Makes no difference which character Cumberbatch is playing really. He's still the vangeful baddie in the dark trenchcoat who has blown stuff up, and must be stopped before he can blow more stuff up.
Anybody remember when this franchise was about exploring?