Another set. This time for Crobat.
Crobat @ Mental Herb
EVs: 76 HP / 212 Def / 220 Spe
Nature: Jolly
Ability: Inner Focus
- Super Fang
- Tailwind
- Taunt
- Quick Guard
Super Fang cuts one enemy's HP in half which lets Crobat's partner turn a 2HKO into a OHKO. Tailwind helps for Speed control and Taunt is mostly used on Xerneas since it can't run a Mental Herb like Trick Room Pokemon could. Quick Guard blocks Fake Out and other priority attacks and pretty much shuts down Prankster Pokemon.
The EVs let you outspeed Weavile, which is the fastest Fake Out Pokemon besides an already Mega'd Lopunny and Ludicolo in the Rain. I honestly don't see a reason to run max Speed since you can't Super Fang Gengar, you're risking a 50/50 against Mewtwo, and Taunt won't do a whole lot to either of them. The HP and Def EVs let you survive Jolly Mega Kangaskhan's Double Edge and you can still take a +2 Xerneas's Moonblast as well. 116 HP / 252 Def / 140 Spe could also be used to outspeed Mega Rayquaza and survive a Primal Groudon's Stone Edge. You'll still have a good chance to die from Overheat pretty much no matter how you EV Crobat, though.
Mental Herb blocks Taunt which can cripple you and Inner Focus stops Fake Out from flinching you. I think these are the moves most people are running, but I remember seeing Whirlwind at one point as well.