Gen 6 was a wasteland with less than 100 new Pokemon released in that generation. But this was also the generation that gave us a freaking frog ninja and, regarding today's POTW, a freaking sword! THAT is badass. Needless to say when I saw its pre-evolution Honedge I knew immediately that I wanted that possessed weapon on my team. The fact that it evolves into the only Pokemon that can effectively switch its stats on a dime between being a wall and a glass cannon is also pretty freaking cool. In fact, Aegislash was so OP that it even got banned back in the day because it could abuse its excellent typing for defensive and offensive coverage, complete with priority and access to boosting moves. Thankfully Aegislash got unbanned later, so now we can march into battle with this sword and shield on our hilt like true knights (Except don't actually do that since it can siphon off your life energy just from touching it).
Lord of Edge
Ability: Stance Change
Item: Life Orb
Nature: Adamant (+Attack -Sp.Attack)
EVs: (HP 252) (Attack 252) (Speed 4)
Moves:
Swords Dance
Iron Head
Shadow Sneak
King's Shield
Set Details:
A set that is equal parts sweeper and tank thanks to Aegislash's unique ability to swap its stats freely from a Carbink damage sponge to a Rayquaza damage dealer. Set up Swords Dance while in shield form since odds are strong you will survive an attack or two in this form, and once you have one or possibly even two, proceed to go all buster sword on your opponents with your dual STAB that have excellent neutral coverage. Iron Head is your strongest STAB and can be used against faster opponents since the form change and transistion to weaker defenses does not happen until your turn passes. Shadow Sneak on the other hand bypasses Aegislash's weak speed in both forms and gives opponents few options to counter since even at base 40 power, Shadow Sneak still KOs many key threats after a Swords Dance coupled with Life Orb. The last slot goes to King's Shield which allows Aegislash to swap back to shield form when your opponent sends in a faster and bulkier counter as well as block any attacking move, with the added bonus of lowering your opponent's attack if the incoming attack makes direct contact. Just be sure to note that King's Shield unlike Protect will not block status moves, meaning you are still helpless against moves like Will-O-Wisp which will completely ruin you. Stat investment goes into exclusively HP and attack, that way Aegislash can be bulky with its shield but also powerful with its sword.
Cursed Sword Tyrfing
Ability: Stance Change
Item: Life Orb
Nature: Timid (+Speed -Attack)
EVs: (HP 4) (Sp.Attack 252) (Speed 252)
Moves:
Autotomize
Shadow Ball
Flash Cannon
King's Shield/Steel Beam
Set Details:
The previous set focused on being a physical tank. This set focuses on being a special sweeper. Set up Autotomize one or two times to jack up your speed to usable levels while in shield form, hit with your dual STAB, and use King's Shield for scouting and damage control against certain physical attackers when they come crashing into your shield. You may also consider using Steel Beam when faced with an opponent bulky enough to wall your weaker attacks, but the 50% HP recoil will spell your doom quickly if you are at or below 60% health (Life Orb recoil factored in). This time your nature and EVs are poured into special attack but mostly speed.
Attack on Pocket Monster
Ability: No Guard
Item: Eviolite
Nature: Adamant (+Attack -Sp.Attack)
EVs: (HP 252) (Attack 252) (Speed 4)
Moves:
Swords Dance
Iron Head
Shadow Sneak
Sacred Sword/Close Combat
Set Details:
Back when Aegislash was banned, there were still plenty of players who used its pre-evolution Doublade since it was able to run a similar, albeit weaker set, thanks to Eviolite boosting its already high base 150 physical defense to insane levels while patching up its weaker base 50 special defense. Same story as its evolved set. Boost offenses with Swords Dance while sponging physical attacks, hit harder with Iron Head, and bypass your lousy speed with Shadow Sneak. Rounding things out is Sacred Sword which handles certain Normal, Dark, and Steel types that its STAB cannot handle alone, though you could opt to run Close Combat instead if you don't mind shedding your awesome defenses with each use in exchange for more power.