Like you said, Staka only got a quickban because its clearly broken. I havent quickbanned anything else and nothing else stands out as deserving of oneJust throwing out here but Pipotchi if you want to ban something, next time it'd be better if you suspect it first or something, rather than quickbanning it with not really much discussion or warning. Don't get me wrong, I'm fine with Stak ban since it's pretty clear what it does to the meta (near-guaranteeed 150 BP STAB gyro ball with 211 attack is clearly overpowered, not to mention it outspeeds nearly everything in TR and has the bulk to take priorities). But if you keep handling the meta this way, I'm afraid we'll have unnecessary bans and too much bans is bad for the meta (see Shared Power).
After Stakataka, there's no mon that rivals it's power, that's why if there will be a possible ban, suspect it first next time.
edit: let me tack a set onto the end of this post that excites me
Charizard-Mega-Y @ Charizardite Y
EVs: 252 HP / 252 Def / 4 Spe
- Fire Punch
- Toxic / Earthquake / Solarbeam
This Zard-Y is flames. A wall with 78/159/115 defenses and a bunch of relevant resistances, it can switch into the likes of Kartana, Buzzwole, scarf Blacephalon and CB Azu amongst other threats. Fire Punch is actually hitting pretty hard thanks to 104 atk and Sun, and it defogs hazards away from setters like fast webs Araquanid and non-ancient power Camerupts, defensive Landorus, Skarmory, etc. Thanks to Sun it also tanks a lot of water type attacks and can be answers to aforementioned Araquanids, Slowbros, and a great all-round switch-in to Scald.
Also, Sun is a strong, underrated playstyle in NS right now. Chlorophyll abusers such as Tangrowth and Jumpluff are much more threatening teammates for instance, although Zard's Sun doesnt last that long.
252 Atk Water Bubble Araquanid Liquidation (70 atk) vs. 252 HP / 252+ Def Charizard-Mega-Y in Sun: 96-112 (26.6 - 31.1%)
252 Atk Kartana Sacred Sword vs. 252 HP / 252+ Def Charizard-Mega-Y: 33-39 (9.1 - 10.8%)
252 Atk Tapu Bulu Stone Edge vs. 252 HP / 252+ Def Charizard-Mega-Y: 224-268 (62.2 - 74.4%) (if fast, is ohkod back by fire punch)
252+ Atk Huge Power Mawile-Mega Thunder Punch (105 atk) vs. 252 HP / 252+ Def Charizard-Mega-Y: 160-190 (44.4 - 52.7%)
252+ Atk Huge Power Mawile-Mega Play Rough (125 atk) vs. 252 HP / 252+ Def Charizard-Mega-Y: 81-96 (22.5 - 26.6%)
252 Atk Victini Bolt Strike vs. 252 HP / 252+ Def Charizard-Mega-Y: 124-146 (34.4 - 40.5%)
+6 252+ Atk Huge Power Azumarill Aqua Jet (80 atk) vs. 252 HP / 252+ Def Charizard-Mega-Y in Sun: 212-252 (58.8 - 70%)
The name of the game is really just pairing it with something that can keep rocks off the field vs the annoying rock type setters. Landorus-T or defensive Espeon are both decent options for teammates although neither of them are too great against Diancie.
You can also run things like Earthquake over Toxic to deny the diancie switchin, or Solarbeam to do better vs Azumarill (you switch into the BD set, and +6 aqua jet does 70 max while solarbeam does 71-84% back to Naughty sets, likely beating both Sitrus and Normalium Azu. Even CB Azu can be switched on in a pinch since its Liquidation underspeeds and does 55% maximum. If you want to definitely beat Normalium Lonely Azu, 60 spa EVs makes sure that Solarbeam will 2hko if its running max speed)