A specialist Pokemon that I trained a while back but really haven't had much of a chance to use - Narcissus the tricky Gardevoir.

_{Name: Narcissus
Pokemon: Gardevoir
Type: Psychic/Fairy
Base Stats: 68/65/65/125/115/80
EV Investment: 4HP/252SpA/252Speed
Nature: Modest (Atk-, SpA+)
Characteristic: Takes plenty of siestas.
Ability: Trace (Copies opponent's ability upon switching in)
Item: ChoiceScarf (x2 Speed - limits your choice of moves to 1)
Moveset: Moonblast, Thunderbolt/ShadowBall/DazzlingGleam, Psyshock, Will-O-Wisp}

You've all heard me ramble on about Gardevoir before, so I won't bore you too much and just get to the point. This is not a standard Gardevoir set, but rather a surprise set. Usually when you see the word ChoiceScarf, you don't think of using a status move. If you want to get locked into an attack, it's an attack that should be dealing damage, and that's exactly what this set is for - except for that one Will-O-Wisp tech.

This set is simple, take advantage of Gardevoir's special tankiness and back it up with a speed boost from the Choice Scarf. You throw out your most powerful moves - Moonblast, Psyshock (for tackling specially defensive sets) and ShadowBall/Thunderbolt for type coverage. Will-O-Wisp is there for cocky ghost/dark types that would try to Sucker Punch you - you burn them and cripple their physical offense. And what makes this better is that if the opponent knows that you're using a choice scarf, they're less likely to suspect a status move. DazzlingGleam is another tech move, perfect for double battles, where you can let Gardevoir's power shine. It might conflict in type coverage and be completely completely useful beside Moonblast, but it does still hit all opponents at once, which could be invaluable.

Do note, for a double or triple battle set, you would be better off using Gardevoir's Hidden Ability - Telepathy (prevents damage from teammates in doubles/triples), however, Trace is always useful.

This was a set created to be used in the Fairy Face-Off last month, where the two largest threats were predicted to be Mega Mawile and Azumarill - both physically offensive threats. Its potency may not match the usual metagame.
This is not necessarily the best set for Aegislash, but simply one that I chose to showcase.