Regarding the Drought discussion, I'm pretty sure that there's nothing that makes Drought overpowering in UU except for the existence of Mega Houndoom. I can't think of anything at all that isn't 2HKO'd by Solar Power boosted, Sun boosted Fire Blast, Dark Pulse, or Solarbeam in the tier besides Chansey. There's just no hope of walling this thing if you don't have room for Chansey on your team, and goddamn, even Chansey can take around 40% from Fire Blast.
There are 3 other stupidly powerful pokemon in the tier, Mega Medicham, Mega Heracross, and Mega Gardevoir. I actually think that Medicham outclasses Heracross at pure wallbreaking unless it's SD Hera, but either one of them hits so disgustingly hard that the prominent physical walls, like Hippowdon have to be at absolutely full health to handle them, which is really lame. Physically defensive Florges and the aforementioned Hippwodon are champs that barely holds it together for you, though.
252 Atk Pure Power Mega Medicham Zen Headbutt vs. 252 HP / 252+ Def Florges: 199-235 (55.2 - 65.2%) -- guaranteed 2HKO after Leftovers recovery
252 SpA Pixilate Mega Gardevoir Hyper Voice vs. 252 HP / 0 SpD Florges: 157-186 (43.6 - 51.6%) -- guaranteed 3HKO after Leftovers recovery
252+ Atk Mega Heracross Rock Blast (5 hits) vs. 252 HP / 252+ Def Florges: 180-215 (50 - 59.7%) -- approx. 88.3% chance to 2HKO after Leftovers recovery
Those Medicham and Heracross calcs don't look too encouraging, but since Florges uses Wish+Protect for healing, it has a decent chance of handling them as long they don't get too many max rolls, and Moonblast will destroy them.
Basically, Medicham, Heracross, and Gardevoir are stupidly strong, but they have shaky counters and very solid checks, so they can be dealt with, and Mega Houndoom is a broken whore.