I really don't get the point of using Stance Change. Yes, in theory it has 60/150/150/150/150/60 stats, but the fact that it needs to run King's Shield and Stance Change to do this makes it extremely predictable and takes up a precious move and ability slot that you could use to aid sweeping otherwise. Unless you want to run mono-coverage, you have to choose between recovery and set-up, recovery making it very easy to wall and set-up making it very easy to wear down. Sweeping-wise, Rayquaza has the same attack stats as Aegi and far more useful STABs to do the job, especially with Gale Wings on the loose.