
Gallade @ Galladite
Ability: Justified
Nature: Jolly
EVs: 252 Attack, 252 Speed, 4 Special Defense
- Close Combat
- Zen Headbutt
- Knock Off
- Swords Dance
With ski-high attack, speed, decent bulk, and access to swords dance and stab close combat, Mega Gallade is one of the 2 pokemon this team is built around. The primary set-up/late-game sweeper for this team. Close Combat for a very powerful stab-move which even resisted an KO some mons (+2 252 Atk Mega Gallade Close Combat vs. 0 HP / 0 Def Latios: 282-332 (94.3 - 111%) -- 62.5% chance to OHKO, +2 252 Atk Mega Gallade Close Combat vs. 0 HP / 4 Def Thundurus: 312-367 (104.4 - 122.7%) -- guaranteed OHKO). Zen headbutt gives necessary coverage, achieving the 2HKO against Clefable, Landorus, and other mons that resist close combat. Knock Off gives coverage for Latias, Gengar (If not wanting to risk zen headbutt), Mega Gardevoir, Gothitelle, Jirachi, etc. Swords Dance boosts Mega Gallade to 858 attack. The specific EVs max out Gallade's attack and letting it speed tie with Latios, Latias, Gengar, and Mega Diancie after mega evolution. Prior to mega the speed allows it to speed tie with Jolly/Timid Mega Altaria, Jolly Mamoswine, Jolly Dragonite.

Bisharp @ Asssault Vest
Ability: Defiant
Nature: Adamant
EVs: 76 HP, 252 Attack, 180 Speed
- Sucker Punch
- Knock off
- Pursuit
- Iron head
Bisharp + Gallade is one of the best power-couples in OU at the moment for good reasons. With this set Bisharp can always live +3 Moonblast from Clefable and 2HKO with Iron Head, can only be 2HKO'd by life orb latios's Draco Meteor with a high-roll and is KO'd by Sucker punch and Knock off. The necessary speed allows Bisharp to outspeed Rotom-W with 219 speed, and standard Defensive Landorus-T. With the Defiant ability it threatens defog users, sticky-web teams, intimidate users, and stat-dropping moves by getting to +2.

Landorus-Therian @ Leftovers
Ability: Intimidate
Nature: Impish
EVs: 248 HP, 244 Defense, 8 Special Defense, 8 Speed
- Earthquake
- U-turn
- Stone edge
- Stealth rock
Mega Gallade and Bisharp need a switch-in for CS Landorus-T, Mega Charizard X, Mega Gallade, Talonflame, Mega Pinsir and other physical attackers. They also need something with a ground-immunity and something to reliably set-up stealth rock. And thus here's Landorus-T who does all of those things, gives U-turn initiative. With this given EV spread it allows Landorus to switch in the maximum number of times on Stealth Rock, check Excadrill, Talonflame, Pinsir, live HP Ice from Mega Manectric, outspeed Modest Magnezone, and still have a slow U-turn.

Rotom-W @ Leftovers
Ability: Levitate
Nature: Bold
EVs: 248 HP, 152 Defense, 108 Special Defense
- Volt Switch
- Hydro Pump
- Will-o-wisp
- Pain Split
One of the best defensive cores in ORAS OU is Landorus-T + Rotom-W. With them on this team it allows for VoltTurn initiative and to be able to whittle things for Gallade and Bisharp to clean up. Hydro Pump allows for Rotom to punish incoming Ground types (Landorus, Mamoswine, Excadrill, etc.) and to have a damaging move that doesn't force Rotom to switch out. Will-o-wisp cripples physical attackers, whittles bulkier and specially offensive pokemon. Pain Split allows for Rotom to recover it's health and to damage other pokemon. This given EV spread allows Rotom to not be 2HKO'd by Mega Manectric's thunderbolt, Landorus's psychic, and to not be OHKO'd by Latios's Draco Meteor.

Sylveon @ Leftovers
Ability: Pixilate
Nature: Bold
EVs: 252 HP, 220 Defense, 36 Special Defense
- Hyper Voice
- Wish
- Heal bell
- Protect
The bulkier pokemon on this team have pretty mediocre recovery. Landorus only has leftovers and Rotom has to rely on painsplit + Leftovers. There is also nothing that wants to take an oncoming Will-o-Wisp. Clefable would work but it's not nearly bulky enough on the Special side nor hits hard enough, and thus comes Sylveon! Sylveon can Wish-pass to the other pokemon, can heal bell away status, and smacks everything that doesn't resist it hard with a Pixilate boosted Hyper voice. The given EV spread allows Sylveon to not be 2HKO'd by Latios's psyshock, to take Landorus's earth power better, and to be able to Wish-pass easier.

Starmie @ Life orb
Ability: Natural cure
Nature: Timid
EVs: 252 Special attack, 252 Speed, 4 Special Defense
- Rapid spin
- Psyshock
- Scald
- Hidden power fire
This team is fairly weak to stealth rock due to the VoltTurn of Landorus and Rotom and Sylveon's necessity to remain at a decent amount of HP, so rapid spin support is necessary. This team also needs a switch into Specs-Keldeo and an offensive special attacker. Starmie also outspeeds the majority of OU except for Raikou, Mega Lopunny and Mega Manectric. Scald 2HKO's Heatran, OHKO's Defensive Landorus-T after stealth rock, Excadrill and Mamoswine. Psyshock OHKO's Keldeo, and smacks specially defensive pokemon on their lower defensive side. Hidden power fire hits Ferrothorn for the 2HKO. The given EV spread gives Starmie the maximum speed possible, the highest possible damage, and for Download users to get an Attack boost.