While Khan is beatable with prediction, prediction is a very piss poor argument. It needs to be banned mainly because it overcentalizes the meta in a way that only Stealth Rock should ever do. Nothing can take boosted Sucker Punch, not even Terrakion, so if it can beat it's checks, they are no longer checks.
Loads of physcial priority users can take boosted sucker punch, like Luc, breloom, or Conk, which are all common. Thats not why it's in question of being banned.
Prediction isn't a piss poor arguement, IT IS THE BASIS OF THE GAME.
Im actually in favor of Khan being banned, but yours is a crap reason.
Centralization isn't why we ban things. Really, we ban things because they do their job 100% of the time, without being stopped by anything. The reason we had excadrill banned is because with sand rush, and his natural bulk and typing to take priority, he can almost guarentee a swords dance, and have insane speed at the same time, then sweep outspeeding scarfers and priority bouncing off. Blaziken is banned because it is has near perfect coverage with HJK and flare blitz, good typing to take all priority moves really well bar aqua jet, combined with more than 1 turn of speed boost so you can't choice scarf revenge it, and that only giratina has the typing and stats to reliable stop him.
WE DID NOT BAN M-GAR BECAUSE IT CENTRALIZED THE METAGAME, OR COULD SWEEP A TEAM. READ THE ANOUNCEMENT FOR PETE'S SAKE. I am sick of people saying that. If that was true then Politoed and Ninetales and Garchomp and Terrakion and salamence would never see the light of day outside Ubers. They are centralizing, but together they keep each other in check and are thought about directly when building a team (
terrakion in particular). Khan is in question of being banned because:
A.) Its speed tier is 100, severely limiting what would counter outside of priority, meaning that what would counter it has to faster than it, requiring a scarf or priority to survive.
B.) The above, combined with it's bulk and sheer power means that a lot of frail fast mons that out speed it, such as Keldeo, can't 0HKO it thanks to it's bulk, and are destroyed when it hits back. Its power and bulk, combined with it's speed make to too much to be revenged easily, or even just taken down.
C.) To revenge it, you mush sacrifice something to do damage, then finish it off with priority, or switch in one of it's counters, Confagrious, dusclops, or whatever, because it will kill them with ease if the don't switch in safely. To remove it from the game literally requires you to sacrifice something. Even with the rocky helmet sets (which have been around forever, seriously, do some research) you still have to sacrifce a mon to kill it, with something ferrothorn, dying so khan can take a bunch of damage from hitting thorn, then being finished by priority.
D.) For example, one can pack a threat that is checked by the same things a M-Khan, and once say, Rocky helmet G-Chomp is dead along with Khan, that threat can sweep and win.
Dear god people, take a second to learn why we ban stuff, LOOK IT UP. Stop crying that it makes it easy to win, or that it's centralizing, or that it takes no team support, or the all too common, WUT LOL OP. (i have seen that 5 times.) Thats not why we ban things here. We are chatting int the pokemon UNIVERSITY. Knowledge about why we ban things is right in front of you. LEARN IT.
KHAN SHOULD BE BANNED BECAUSE OF THE REASONS ABOVE THIS PARAGRAPH AND POSSIBLY SOME OTHERS , BUT NOT THE CRAP ONES LISTED IN THIS PARAGRAPH.
I Can say that for sure ferrothorn would run rocky helmet without khan. They did it last gen to stop things like CC terrakion and OHKO back with Gyro ball.
On a small note that has nothing to do with the agruement for or for not banning khan, Its fun to D-Bond this guy with Banette, ensuring it's death.