So I spent a little while thinking about my vote and basically reading the comments on this thread, while taking into account my own experiences in the meta as well what I've observed from "higher level play". Here goes.
re Kangaskhanite: I'm going to agree with the people that think it's
not broken. Indeed, Mega Kangaskhan is one of the more powerful threats in Doubles atm, and while yes it is predictable, there's a reason for that: it's very effective at what it does. It packs two roles into one: an offensive utility mon with Fake Out and a sweeper with Power-Up Punch. However, the means in which it's checked doesn't require you to run something obscure. Its checks are rather effective Pokemon / strategies in the metagame, and the amount of countermeasures towards beating it are rather widespread. Regardless of Mega Kangaskhan's influence, you'll still find at least one Intimidate user per team or at least a good Fighting- / Ghost-type. That's not even mentioning how MeKanga is utterly screwed by Will-O-Wisp or double-targeting. Furthermore, while yes MeKanga can run ways to bypass bulkier Ghost-types, dissuade double-targeting, and even burns through the use of Crunch, Protect, and Facade, respectively, at what cost does it come by? What will Mega Kangaskhan forgo in order to beat its usual checks? Will it relinquish its utility capabilities with Fake Out; will it become more susceptible to revenge killers by dropping sucker punch; or will it just forget the idea of sweeping altogether and push Power-Up Punch aside? Yes Mega Kangaskhan can deviate from its standard set, but it has to sacrifice something crucial in order to do so, and this leaves it vulnerable to quite a few other threats as a result. Overall, its sheer predictability, inability to counteract its checks without losing its usual effectiveness, as well as the raw ubiquity in its checks makes me believe that Mega kangaskhan is not broken. As for how it shapes the meta, I don't feel its gives off a positive nor a negative influence. All it does it require you to adjust your team ever-so slightly to beat it, and that's pretty much the same deal with any top tier threat, really.
re Charizardite-Y: This isn't a Pokemon that I consider to be broken either. In fact, I find that Charizard-Y brings a rather positive influence: it makes sun good. I'm assuming most people that are posting here played BW Doubles, so we all know how "great" sun teams where at that time. I feel as if Charizard-Y increases the diversity in this meta by making sun mons and chlorophyll users a thing. You can run rain, hail, sand, trick room, sun, and just about anything and be successful, that's what's nice about this meta. The fact that sun teams are usable now, let alone the premier weather, is pretty exciting. Now, I don't subscribe to the sub-par reasoning, "this Pokemon brings something good for the meta, don't ban it", I'm simply stating the positives towards keeping Charizard-Y. There are a few things that keep it from being broken in my eyes. The first of which is its speed stat, while not "slow", it's not necessarily fast either considering things like Terrakion and Thundurus-T can outspeed and KO. The second is the weather nerf, which makes it rather easy to stall out sun turns if needed. The third, is the fact that it can't boost its special attack in any way. If it could use something like Quiver Dance or Nasty Plot and then ram through the opposing team with infinite sun-boosted heat waves, I'd hop on the ban hammer wagon in a heart beat. Fourth, its checks aren't very hard to come by. As stated by almost everyone else, Heatran and Tyranitar won't all of a sudden fall of the face of the earth if Mega Zard-y leaves, they're being used due to the fact that they're good; the ability to check zard-y is just another goodie for them. Lastly, it can't carry an item. This means that it can't pull off any surprises with a scarf set or heal itself with a sitrus berry, or boost its offenses with a life orb, etc. In conclusion, It's a very powerful Pokemon that's just on the edge of being broken, but it just doesn't have that "something-something" to make it so.
re Giratina-O: At first I didn't think it was a bad idea suspecting it. I mean Giratina-O does some pretty neat things in that it basically makes 4 out of the 5 or so S-rank mons its bitch. On top of that, it seemed that its weaknesses to Ice-, Dragon-, and Ghost-types moves would help keep that colossal bulk in check; however, judging by the counter-arguments towards a tina suspect as well what I could gather based on speculation alone, it's just all the more apparent that it's not the best idea. The thing with Giratina-O that strikes me is that not only is it incredibly bulky, but it hits deceptively hard too. It can't hold an item, true, but that's not a very strong case when its default item basically boosts both of its STABs by 20% with no catches. The other thing is that you have to specifically dedicate something to beat it and even then you're not assured to take it down. So lets say you run Bisharp or Ttar to take down Giaratina-o, but then it runs something like Will-O-Wisp to screw them over. Now lets say wisp tina becomes popular on the ladder, then more of tina's checks would start running lum berry. But Giratina isn't just limited to wisp, it can just forgo the move and 2HKO ttar and OHKO bisharp with aura sphere. My point here is that Giratina can adjust its moveset to bypass almost every single countermeasure you can try and at the same time, it doesn't appear as if its performance is hindered in any way. This isn't even acknowledging support it can provide by spreading burns and even screw over faster checks with Tailwind or freaking shadow sneak. Simply put, it doesn't appear as if there's a way to beat Giratina-o until you've scouted the moveset, and at the point, you better be lucky enough to have something that can deal with that exact combination of moves. In short, it's just another Uber and should stay that way.
re Lugia: I'm not even going to go into this one. This thing is basically Cresselia x2 squared. So yeah, fuck that. I'd rather not deal with an improved Cresselia clone that can still be run
with Cresselia for more support-mon nightmares... /me shudders
As for my vote...
No Suspect.
Let me just say that this is one of the most balanced meta I've ever had the pleasure of playing. While it is balanced, it isn't bland either! The amount of strategies you can run and still be successful is almost immeasurable. I feel as if that banning anything will really screw with this great meta. Banning Kanga will lose out on a really cool physical attacker, banning Zard-Y means that sun teams go back to being dead, and freeing Giratina-O or Lugia will just introduce an unhealthy amount of overcentralization. The meta is fine just the way it is. Everything can be checked in one form or another without restricting team building. I'm not opposed to any sort of suspect (especially if better arguments are presented), but I think this route is probably the best.
tl;dr Mega Kangaskhan is not broken. Mega Charizard-Y is not broken. Leave Giratina-O where it is. Fuck Lugia. No suspect.
