I'm only vouching for Megagross, P2 and Gren to be banned, since they're incredibly annoying on both sides. They're not invincible, but they make the game pretty boring, and I don't thin that's gonna change anytime soon. Especially due to their capacity of just breaing through entire teams I rarely used Megagross and was bored by my own P2. They just make the game boring. Mega Meta sweeps entire teams by switching on at the right time. Greninja can play around with immunities and even destroy everything a la Megagross in some cases. P2 either sweeps everything, stalls everything or just sits there and waits to die, while its opponent craves for that crit. Well, unless something has a hard-hitting Fighting-type move. Megagross can be tailored for each challenger and sweep at least a quarter of the leaders. While there are other god tier threats out there, Garchomp and Aegis, the former doesn't break the game, it's just a pretty complete and versatile pokemon to use, and the latter can be rendered nearly useless with certain moves (Taunt says hi), and still suffers from some pretty common weaknesses and shortcomings.
Even with these gone, there are a lot of great mons out there, such as GREGORY THE ALMIGHTY , and stuff like Arcanine, Tsareena, Rotom, Araquanid, Excadrill, etc. Anyways, there are obviously some pretty daunting strats that don't involve any of these, such as most of Elliot's stall core, all of Lilly's, and even things like the infamous Roy, but those can be beaten by most good teams. Meta will probably go down in usage quite a bit, but imo it's still pretty great, as it can set rocs, explode, and has a mean green Weaness Policy + Agility set (among other things that set it apart from other mons). P-Z is a way healthier alternative for P2 as well (I'm using one next season actually). And it's funnier to try to come up with fresh strategies for your team, rather than just using the meta's prized mons. Anyways, it's all for fun, and these bans seem fair bar edgyslash. But anyways this was incredibly fun and I hope I can stick around for it next year. Also Gliscor is reaky good it can bulk things. Hard things.