I think that mixed Aegislash with the beloved Ghost/Fighting coverage is pretty good, but not in a Swords Dance set. I use:
Aegislash @ Spooky Plate
Quiet, 252 Atk, 252 SpAtk, 4 SpDef
Shadow Ball
Shadow Sneak
Sacred Sword
King's Shield
As it's been said before, opponents don't really know if...