Um, Weakness Policy Aegislash is really not a thing. It's far too situational. The closest set to a offensive Aegislash that is even remotely viable in Ubers is something like this:
Aegislash @ Spooky Plate
Ability: Stance Change
EVs: 252 Atk / 248 HP / 8 SDef
Adamant Nature
- King's Shield
- Swords Dance
- Shadow Sneak
- Iron Head
This KOs Mega Gengar after a round of Stealth Rock damage, while Mega Mewtwo Y takes 73-87%. You still survive any +2 hit from Xerneas, while Iron Head + Sneak kills. Notably, standard Ho-Oh is 2HKOed at +2, as are things like Palkia, Kyogre, and offensive Landorus-T (at +1). It's also quite easy to set up an SD with Aegislash's typing and bulk. Yveltal is everywhere though, and Ground-types are still a huge pain to deal with.
Anyway, Aegislash is fine where it is IMO. It checks most Fairies, albeit being in a bind against SubGeoXern + being wisp bait. Outside of that, it provides utility against Gengar and soft-checks Mewtwo. Still, it accomplishes very little outside of this + being able to emergency Toxic Eleceus + scraping by Mega Luc if using Shadow Ball (lol). Also, Fire, Ground, Ghost, and Dark-type weaknesses mean any of Ground-types, Ho-Oh, Yveltal, Darkrai, Blaziken, and Ghostceus can do as they like with it, and this prevents it from rising any higher than B.
Aegislash @ Spooky Plate
Ability: Stance Change
EVs: 252 Atk / 248 HP / 8 SDef
Adamant Nature
- King's Shield
- Swords Dance
- Shadow Sneak
- Iron Head
This KOs Mega Gengar after a round of Stealth Rock damage, while Mega Mewtwo Y takes 73-87%. You still survive any +2 hit from Xerneas, while Iron Head + Sneak kills. Notably, standard Ho-Oh is 2HKOed at +2, as are things like Palkia, Kyogre, and offensive Landorus-T (at +1). It's also quite easy to set up an SD with Aegislash's typing and bulk. Yveltal is everywhere though, and Ground-types are still a huge pain to deal with.
Anyway, Aegislash is fine where it is IMO. It checks most Fairies, albeit being in a bind against SubGeoXern + being wisp bait. Outside of that, it provides utility against Gengar and soft-checks Mewtwo. Still, it accomplishes very little outside of this + being able to emergency Toxic Eleceus + scraping by Mega Luc if using Shadow Ball (lol). Also, Fire, Ground, Ghost, and Dark-type weaknesses mean any of Ground-types, Ho-Oh, Yveltal, Darkrai, Blaziken, and Ghostceus can do as they like with it, and this prevents it from rising any higher than B.