My OP Pokemon Team (Double Battles)

[xMewTwo]

Mega Rayquaza
Item-Life Orb
-Dragon Ascent
-D Dance
-Dragon Claw
-Extreme Speed
Kyogre
Item-Blue Orb
Origin Pulse
-Thunder
-Ice Beam
-Protect
Arceus
Item-Toxic Plate
-Judgement
-Ice Beam
-Recover
-Extreme Speed
Xerneas
Item-Power Herb
-Geomancy
-Dazzling Gleam
-Thunderbolt
-Flash Cannon
Yveltal(Life Gain)
(the item that gives you life for each hit you make)
-Oblivion Wing
-Dark Pulse
-Steel Wing
-Phantom Force
Mewtwo/Victini
Item-Leftovers|Item-Choice Scarf/Flame Plate
-Psystrike -V-Create
-Aura Sphere -Physic
-Ice Beam -T-Bolt
-T-Bolt -Protect

 

[Zukrad]

Right Now, Im in cellphone, so I can't rate that well, but so far

-Replace Mewtwo/Victiny for Primal Groudon, he is one of the best mons in the game in doubles
-Use lefties on Yveltal
-Use Moonblast on Xerneas

 

[Zukrad]

Now my actual rate

Spoiler: Old Set

Mega Rayquaza
Item-Life Orb
-Dragon Ascent
-D Dance
-Dragon Claw
-Extreme Speed

Spoiler: New Set

Rayquaza @ Life Orb
Ability: Air Lock
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Dragon Ascent
- Swords Dance
- ExtremeSpeed
- Protect

Spoiler: Reasoning

First, not a single of your Pokémon (besides Kyogre) has protect
Protect is the most important move in doubles, so keep that in mind
Mega Ray's role is pretty straight forward, go in, mega evolve, protect since everyone will gain up on him, and hit something hard before dying. One great perk to using Mega Ray is Delta Stream, it turns him into a dragon type with a flying STAB. Mega Ray is pretty frail though, so he's usually the first to go. Overall a decent poke but he's mainly there for Delta Stream abuse due to his frailty.
Also with a Pokémon like RayRay in a Meta like doubles SD->DD all the way

Spoiler: Old Set

Kyogre
Item-Blue Orb
Origin Pulse
-Thunder
-Ice Beam
-Protect

Spoiler: New Set

Kyogre (Kyogre-Primal) @ Blue Orb
Ability: Primordial Sea
EVs: 172 HP / 252 SpA / 84 Spe
Modest Nature
- Origin Pulse
- Psych Up
- Protect
- Ice Beam

Spoiler: Reasoning

Psych Up Kyogre is really cool, since you can Psych Up opposing Xerneas or even your own teammate Xerneas and get a +2+2+2 Kyogre
Origin Pulse is there for obligatory, powerful, multi hitting STAB. Ice Beam is there for coverage, for Primal Groudon, and so he's not complete wide guard fodder.

Spoiler: Old Set

Arceus
Item-Toxic Plate
-Judgement
-Ice Beam
-Recover
-Extreme Speed

Spoiler: New Set

Arceus-Steel @ Iron Plate
Ability: Multitype
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Judgment
- Protect
- Earth Power
- Icy Wind

Spoiler: Reasoning

Geoxern is a problem no matter where you go, so Arceus Steel is the answer to that. Hitting Xerneas hard, most likely OHKOing him if Xerneas has taken prior damage. Earth Power is there for any Primal Groudon mainly, but is also there for anyone that resists his Steel Judgement. Icy Wind is an annoying move, slowing down both opponents allowing Arceus and co to outspeed them. Arceus Steel also appreciates having Primal Kyogre out on the field, granting him an immunity to fire.

Spoiler: Old Set

Xerneas
Item-Power Herb
-Geomancy
-Dazzling Gleam
-Thunderbolt
-Flash Cannon

Spoiler: New Set

Xerneas @ Power Herb
Ability: Fairy Aura
EVs: 184 HP / 28 Def / 252 SpA / 44 Spe
- Moonblast/Aromatherapy
- Dazzling Gleam/Aromatherapy
- Protect
- Geomancy

Spoiler: Reasoning

Geomancy Xern is pretty straight forward. While Dazzling Gleam isn't as potent as Moonblast, it still hits both opponents hard. Aromatherapy is there to cure himself, and any teammates of any status conditions. Geoxern also pairs up really well. Xerneas can protect after a Geomancy and then Kyogre can psych up on him safely, allowing them to sweep together. They also put a lot of pressure on Primal Groudon, he can't check them both on his own.

Spoiler: Old Set

Yveltal(Life Gain)
(the item that gives you life for each hit you make)
-Oblivion Wing
-Dark Pulse
-Steel Wing
-Phantom Force

Spoiler: New Set

Darkrai @ Life Orb
Ability: Bad Dreams
EVs: 40 HP / 252 SpA / 216 Spe
Timid Nature
- Dark Pulse
- Ice Beam/Thunderbolt/Focus Blast/Nasty Plot
- Dark Void
- Protect

Spoiler: Reasoning

Darkrai has a very high base Speed, letting it outpace most of the metagame with little investment, and thanks to its great Special Attack, it can deal great damage to all of the metagame, 2HKOing most of them and opening up spaces for other team members to set up or sweep the opponent's team.
And the most important thing, Dark Void

/

Spoiler: Old Set

Mewtwo/Victini
Item-Leftovers|Item-Choice Scarf/Flame Plate
-Psystrike -V-Create
-Aura Sphere -Physic
-Ice Beam -T-Bolt
-T-Bolt -Protect

Spoiler: New Set

Groudon-Primal @ Red Orb
Ability: Desolate Land
Level: 50
EVs: 4 HP / 244 Atk / 4 Def / 4 SpD / 252 Spe
Adamant/Jolly Nature
- Precipice Blades
- Fire Punch/ Overheat
- Rock Slide/ Stone Edge/ Substitute/ Thunder Wave/ Roar
- Protect

Spoiler: Reasoning

Is Primal Groudon... nuff said