Well, Grass and Fighting are a really great fighting combination. It's defenses are above average, but its typing provides it a wonderful set of resistances. 108 Speed is higher than most things out there and most things faster than it usually won't OHKO it unless they're specsed or something. After a boost it breaks through the Ferrothorn Jellicent combo and slams other defensive Pokemon like Hippowdon, Blissey, Vaporeon, and even Reuniclus.How so? Is it because Virizion can easily switch in on the QuakeEdge combination, despite its 72 Defense, and set up an SD as the opponent switches?
It doesn't have the best Attack and Special Attack for SDing or Calm Minding, but they work.
I'm not saying its broken, but I've used the Swords Dancer enough to understand how great it is... it usually kills at least two Pokemon in a battle for me. I use Swords Dance/Leaf Blade/Close Combat/Stone Edge with Leftovers to great effect. Truly one of the best members you can use on a Fire/Grass/Water Core. I recommend trying it with Heatran/Chandelure and the bulky water of your choice. Also combos great with Lati0s--it's ability makes it an excellent Tyranitar slayer, too.