WouW
Smash Lord
#078 Rapidash
Fire
Flash Fire: Boosts the power of Fire attacks when hit by a Fire-typed move OR:
Run Away: Can always run away from wild battles. No effect in battles.
65HP/100Atk/70Def/80SpA/80SpD/105Spe
Double Status
Rapidash@Leftovers/Wide Lens
Flash Fire/Jolly
252Atk/252Spe/4HP
Hypnosis
Will-o-Wisp
Flare Blitz
Megahorn
Simple: Use Rapidash' great speed to Hypnosis whatever you're fighting, then Will-o-wisp whatever comes in. Then proceed to do as much damage as possible with your other two moves. With Wide Lens, you can boost the accuracy of Hypnosis, Will-o-wisp and Megahorn if you want to miss less often.
Choice
Rapidash @ Choice Scarf
Flash Fire/Jolly
252Atk/252Spe/4HP
Flare Blitz
Megahorn
Iron Tail
Double-Edge/Return
Hit stuff with great speed, potentially Flash Fire, three Base-120 powered moves and 328 attack. Flare Blitz is your main attack, Megahorn to hit Super Effective against Darks and Psychics, Iron Tail vs. Rocks and Double-Edge for filler. If you hate DE's recoil, replace it with Return.
Choice Band works as well, but replace Adamant with Jolly if you want to do that.
Mixed
Rapidash @ Life Orb
Flash Fire / Mild/Rash
4Atk/252Spe/252SpA
Fire Blast
Hidden Power Grass
Megahorn
Hypnosis
Fire Blast for STAB/Flash Fire, Hidden Power Grass beats most counters like Gastrodon or Quagsire, Megahorn beats the common walls and Hypnosis what you can't take out directly. Nature depends on what you think is less important: Mild for less defense, Rash for less Special Defense.
Other Options:
Choice set: Double Kick can be used to break subs and hit Rocks or Steels. Baton Pass can be obtained from XD, and you can use Agility combined with that.
EVs:
Physical sets: Max out Attack and Speed, obviously. The mix set needs all SpA it can get, and therefore it gets Mild/Rash with maxed SpA EVs.
Troublesome Pokémon:
With 65/70/80 defenses it certainly isn't too bulky. Rapidash has nothing against Fires, and Waters usually beat it as well, although the Mix set counters Waters. Lanturn walls the Mix set, despite HP Grass, though.
Written by WouW