I've already made some points in a previous post, but since i've been sick of seeing Khan everywhere and was bored, decided to make an alt to test one thing that kinda bothers me about her. Unlike many other Pokemon, Khan can literally be tossed into any old team and be guaranteed to do something, as long as you're competent enough to not be
this guy. So, for shits and giggles, I tossed her and Gengar (so i have a shaky Khan check) into my Bug mono, made an alt, and played a bunch of matches on the ladder.
In the posts I've been seeing, people seem to be forgetting that Khan can switch out vs. the few things that she can't kill in 1 hit, or vs. things that are 99% of the time going to go for will o wisp. Volcarona makes an excellent switch for a vast majority of things that'll check Khan, namely Will o Wisp spreaders, Ghost types in general, and Fighting types other than Terrakion or Keldeo. Since a lot of you people are suggesting Choice Banding something with a fighting move to check Khan, most bugs can freely switch into fighting moves, Quiver Dance, and proceed to tear a new hole into your team. Khan is also good for luring your typical "counters" that my Volcy eats for breakfast each morning, like Skarmory and Ferrothorn. So imagine what'll happen if someone pairs it with Magnezone...
Khan has a huge movepool. Sure, the standard PuP/Sucker Punch/Return/filler works wonders against lots of teams, but you can always change one or more of these moves to something that eliminates things that the rest of your team has problems with. For example, I've tested Earthquake and Aqua Tail, since Fire and Rock types are a huge problem for the rest of the team. Aqua Tail is a somewhat gimmicky way to get rid of Rhyperior, something that isn't ohko'd by Return or PuP and could cause massive problems for the rest of the team. Now, I'm not suggesting everyone run Aqua Tail on Khan; but my point is that her moveset can easily be tailored to the needs of the rest of the team. While most people run max atk/max speed Jolly, Khan can viably run a bulkier spread (max hp/max atk Adamant, perhaps) which keeps her from being picked off by Mach Punches from common shaky checks. A support set (with Wish and Seismic Toss) can also be good for stall teams.
From my experience just tossing Khan into any old team, she's far from being reasonably balanced for OU play, considering that I could do far more work with her tossing her into a random team than I can with any reasonably balanced OU pokemon. Khan can be used not only as the main star of the show, but as a way to reliably remove checks for the rest of the team or to support with Wish. With a skilled player actually building around her attributes, the results are likely to be devastating. I support a ban.
http://replay.pokemonshowdown.com/pokebankoubeta-69319364 <-- after sac'ing something to a (likely to be choiced) Infernape, Khan mindlessly blows through this team. It was literally a matter of just picking a move that could hit my opponent and using it.
(more examples to come, maybe)