I have a non-EV'd (yeah I know, but it's old, since my Sapphire days) Skarmory that I use alongside my other Pokes, which usually vary among Swampert, Lucario, Porygon-Z if I'm feeling risky, Froslass if I feel like destinybonding, and Latias if I'm feeling destructive (hey this is the battle tower, not competition, right?). xD
I'm thinking about getting a better Skarmory later with Sturdy to resist those 1HKOers later in the tower.
The moveset I usually use is:
Toxic
Rest
Spikes
Aerial Ace
The last move is useful against double-teamers. Skarm is usually the one I'm left with when the rest of our teams are out and it's just a 1-on-1. Toxic and AA slowly but surely finish them off while suffering little damage myself, resting when necessary.
I suppose I'll sort out which EVs/Nature I'll need as I'm breeding one.