Whimsicott

Whimsicott's Prankster ability gives all its non-attacking moves +1 priority, making Tailwind and Memento reliably fast regardless of Speed tiers. Mental Herb lets it set Tailwind through opposing Encore attempts, allowing Whimsicott to stack Tailwind turns even against mirror Whimsicott. Memento is the key support move here: dropping the target's Attack and Special Attack by two stages makes it easier for Tauros or Camerupt to survive long enough to get the Anger Point boost from Storm Throw. Intentionally frail with only max Speed investment so it can be KOed quickly by Garganacl's Explosion to free up a slot for Pinsir.