I'm strongly against this suspect test. People have been saying Aegislash will eventually be banned since before XY was even released and I honestly never saw why. Yes, it does have a rather big number of sets and some of them have different checks and counters, but so do a lot of Pokemon and that never meant something is broken. You could argue the "number" of sets is the thing that got Genesect banned, but it wasn't the only thing. Aegislash is indeed meta-defining, and one could argue that it's also overcentralizing, but then again so were a lot of other things in the past, and so are a lot of things right now other than Aegislash. Why did Assault Vest Azumarill spike up in usage? Keldeo. Why did Excadrill suddenly start running Mold Breaker earlier in the metagame over like, Sand Rush to abuse opponent's sand or one's own sand? Rotom-W and other Levitating mons. Why does Garchomp sometimes have Fire Blast? Why does Latios use Psyshock over Psychic? etc. Every Pokemon in the metagame can force something else to use a certain move, item, or moveset to have a way to counter said Pokemon; and as far as I know, that's the definition of overcentralizing, to make Pokemon [People] feel like they're forced to run something specific just because a certain other Pokemon exists. It's true that some Pokemon can be more overcentralizing than other Pokemon and some of them can restrict teambuilding like Shuckle did in RU, or like Mega Kangaskhan did in OU before it got banned, but I don't think that's the case for Aegislash. You could argue that it's the only reason for Scizor to be running Knock Off (I've heard quite a few people say that on PS), and while it's probably a big reason its not the only one. Knock Off is one of the best moves in general and really great to have, and Aegislash is definitely not the only reason one would run Knock Off on their Scizor.
Right now, Aegislash is holding many Pokemon back from their full potential; Mega Gardevoir and Mega Medicham are two examples. But so is Talonflame, who is pretty much the reason Volcarona dropped this generation and the reason so many other Pokemon aren't seen, isn't that overcentralizing in the same way that Aegislash is?
I haven't read much of the thread so I don't know the reasoning behind some people's opinions about wanting Aegislash gone, but I'll say it anyway. I guess the reason why Aegislassh can be identified as broken is the amazing defensive and offensive typing, good movepool, King's Shield, and the amazing stat spread. Those combined don't necessarily make Aegislash broken. The typing still gives it weaknesses to Ground- and Fire-type moves, two of which are common in OU from my experience, and with strong users in Excadrill and Charizard, as two examples. Its movepool is good however, and I guess I can't really argue about that, and so is its stat spread. But again, those are never a reason for a Pokemon to be broken. King's Shield on the other hand, can cause some mind-games, but mind-games is Pokemon anyway, since it all comes down to prediction and prediction can go both ways.
Aegislash is a metagame defining Pokemon, and as overcentralizing as any other Pokemon in the metagame, and I would compare it to 4th gen Scizor really, who was also #1 in usage all the time and was centralizing in possibly the same way, and it also created mindgames with U-turn.