Sylveon attack spammer set
Item: Pixie plate (Powers up fairy-type moves)
Nature: doesnt really matter with this set
Ability: Cute Charm (makes him more defensive)
Moonblast (Sweeper move)
Draining kiss (heals 75% of the damage dealt)
Swift (Gets rid of poisen and fire types and never misses)
Dazzling gleam (does a crap load of damage and hits both enemies in double battles)
Sylveon is pretty strong with special attack, so Moonblast is nice to use.
Draining kiss gives alot of health back, and is for some reason a special attack.
Swift can cover up the not-very-effectives on poisen and fire and never misses.
Dazzling gleam does alot of damage and hits both targets. spam it in Battle maison double battle mode, and you destory evrything.
Pixie plate makes fairy moves even more powerful.
For cute charm to work, you have to get a melee on Sylveon first, and then it fas in love and has a low chance of actually attacking. also deals with melee moves.