ORAS AAA 
Important Mechanical Changes:
- Burn deals 12.5% per turn, not 6.25%.
- Rotom formes can only use moves from Electric, Ghost, and their current forme's typing in addition to their normal movepool.
- Prankster affects Dark-types.
- Soul Dew boosts Special Attack and Special Defense of Latios and Latias by 1.5x.
- Dark Void's accuracy is 80%, and it is not restricted to Darkrai.
- -ate abilities grant a 1.3x power boost, not 1.2x.
- Gale Wings grants +1 priority to all Flying-type attacks regardless of the user's HP.
- Base critical hit rate is 1/16 instead of 1/24.
- Normalize no longer boosts the power of affected moves.
- Mega Evolution does not increase the Pokemon's Speed nor activate its Ability on the turn of Mega Evolving.
- Destiny Bond does not fail with multiple uses
Click here for sample teams
You can play ORAS AAA on PS! with the following code:
/chall [user], gen6ou@@@2 Ability Clause, !Obtainable Abilities, -Arena Trap, -Contrary, -Fur Coat, -Huge Power, -Illusion, -Imposter, -Parental Bond, -Protean, -Pure Power, -Simple, -Speed Boost, -Wonder Guard, -Archeops, -Bisharp, -Chatot, -Dragonite, -Keldeo, -Kyurem-black, -Mamoswine, -Regigigas, -Shedinja, -Slaking, -Smeargle, -Snorlax, -Suicune, -Terrakion, -Weavile, -Dynamic Punch, -Zap Cannon, +Aegislash, +Blaziken, +Deoxys-Defense, +Deoxys-Speed, +Genesect, +Greninja, +Landorus
Banlist:
Things that are banned from Gen 6 OverUsed in addition to:
Abilities
Arena Trap, Contrary, Fur Coat, Huge Power, Illusion, Imposter, Parental Bond, Protean, Pure Power, Simple, Speed Boost, Wonder Guard
Pokémon
Archeops, Bisharp, Chatot, Dragonite, Keldeo, Kyurem-Black, Mamoswine, Regigigas, Shedinja, Slaking, Smeargle, Snorlax, Suicune, Terrakion, Weavile
Clauses
OU Clauses, Ability Clause-teams are limited to 2 of the same ability, this includes "variants" such as Teravolt and Turboblaze.
Moves
Dynamic Punch, Zap Cannon
Unbans
Aegislash, Blaziken, Deoxys-Defense, Deoxys-Speed, Genesect, Greninja, Landorus-I
Things that are banned from Gen 6 OverUsed in addition to:
Abilities
Arena Trap, Contrary, Fur Coat, Huge Power, Illusion, Imposter, Parental Bond, Protean, Pure Power, Simple, Speed Boost, Wonder Guard
Pokémon
Archeops, Bisharp, Chatot, Dragonite, Keldeo, Kyurem-Black, Mamoswine, Regigigas, Shedinja, Slaking, Smeargle, Snorlax, Suicune, Terrakion, Weavile
Clauses
OU Clauses, Ability Clause-teams are limited to 2 of the same ability, this includes "variants" such as Teravolt and Turboblaze.
Moves
Dynamic Punch, Zap Cannon
Unbans
Aegislash, Blaziken, Deoxys-Defense, Deoxys-Speed, Genesect, Greninja, Landorus-I
Everything done for me courtesy of berry , full old gen megathread to come in the future!