Gardevoir for S-Rank is something I certainly agree with. Gardevoir can do so many things and is one of the best psychic types. Offensively it is far more dangerous than any other Psychic type in NU with its vast movepool from Psychic to Energy Ball, from Reflect to Thunder Wave and from Thunderbolt to Imprison.
Its biggest flaw is its weakness to Skuntank. The lack of speed boosting can be somewhat annoying as well.
But Gardy's insane versatility more than makes up for it.