Fairies are actually pretty good. I've used a few on my team. Mega Mawile with its huge power, swords dance, and sucker punch is SCARY. Togekiss with serene grace, thunder wave, and air slash prevents the opponent from attacking 68% of the time, and Azumarill with huge power, belly drum, and aqua jet can clean house too. Klefki is a great prankster user with its thunder wave and screens and whatnot. Never used Gardevoire, so I really don't know just how good it is.