>>17649667Assuming that Quagsire comes in after something has died, so he can come in fresh.
252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 252+ Def Quagsire: 198-234 (50.2 - 59.3%) -- guaranteed 2HKO after Stealth Rock and Leftovers recovery
Quagsire uses Curse
252 Atk Aerilate Mega Pinsir Return vs. +1 252 HP / 252+ Def Quagsire: 133-157 (33.7 - 39.8%) -- 90.4% chance to 3HKO after Stealth Rock and Leftovers recovery
Add in Stealth Rock and that's minimum damage rolls 96.2%.
So Quagsire only has the so-so chance of actually getting a curse off and living to recover if he comes in after something dies (or on a switch) with 100% hp, but he will not be able to if they run Adamant nature or Thrash instead of Return.
>>17649686I'm sure the Pinsir player will be so upset taking to hits of rocky helmet damage as he sweeps the rest of your team. (Remember Pinsir is a late game cleaner, so Mandibuzz will probably just be one shot!)
Also
>Playing 3v3