Feb 4, 2015, 02:53 PM
It depends if you have Tailwind support, Screens support or something else, but if want a guaranteed 2HKO on a bulky Sylveon, you need at least Adamant 252 Atk EV, then you can put the rest of them into something else. I would invest 212 HP / 252 Atk / 4 Def / 36 SpD / 4 Spe just to take special-neutral hits better and to outspeed a 0 Spe Adamant Scizor (just in case)
252+ Atk Life Orb Scizor Bullet Punch vs. 108 HP / 196 Def Sylveon: 109-133 (59.2 - 72.2%) -- guaranteed 2HKO
252+ Atk Life Orb Scizor Bullet Punch vs. 108 HP / 196 Def Sylveon: 109-133 (59.2 - 72.2%) -- guaranteed 2HKO