VGC RayOgre

[Megahorn]

Strategy: Rayquaza and Kyogre ensure monitoring of time against Goudon based team. Thundurus-I is the speed control, taunt opponents in fast priority for media and bait for Groudon. Scizor is the counter Xerneas after setup. Smeargle is a help against the Kanga Trick Room. Clefary is a support to keep high the PS during Kyogre Water Spam.

I need to comment on the choices and Evs / nature suitable :)

Kyogre @ Blue Orb
Ability: Drizzle
Level: 50
EVs: 4 HP / 4 Def / 244 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Water Spout
- Ice Beam
- Scald
- Protect

I chose Kyogre because blue is my favorite color. I can checkare Special Groudon and do very great damage due to the dual STAB Water.


Rayquaza @ Life Orb
Ability: Air Lock
Level: 50
EVs: 164 HP / 252 Atk / 4 Def / 4 SpA / 84 Spe
Naughty Nature
- Dragon Ascent
- Extreme Speed
- Overheat
- Protect

I chose Rayquaza because with Air Lock can lock the opponent who check Groudon Kyogre.

This pair is my double legendary with which I will end my avverario shots of STAB when taken momentum.

Smeargle (M) @ Focus Sash
Ability: Moody
Level: 50
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk / 0 Spe
- Crafty Shield
- Wide Guard
- Dark Void
- Spiky Shield


Smeargle Bulky. It 'a stand against the Trick Room. Hypnosis helps against Gravity + etc ... Wide Guard because this is the dual format
Dark Void because it is broken
Pumped in defense to withstand twice Kanga attack that evades the Focus Sash.


Thundurus @ Sitrus Berry
Ability: Prankster
Level: 50
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk / 30 Def / 30 SpA
- Thunderbolt
- Hidden Power [Water]
- Taunt
- Thunder Wave

Thundurus causes supporters opponents. It reduces the speed of all non eletric / ground with Thunder Wave. It 'a bait to Groudon because often played with or without HP Ice.

Scizor @ Lum Berry
Ability: Technician
Level: 50
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Bullet Punch
- Bug Bite
- Swords Dance
- Protect

Scizor is the plan B against Xerneas GeoPumped and one secondary swepper with Sword Dance + double STAB Priority.

Clefairy @ Eviolite
Ability: Friend Guard
Level: 50
EVs: 252 HP / 172 Def / 84 SpD
Bold Nature
- Moonblast
- Follow Me
- Helping Hand
- Protect

Clefairy has the ability that reduces by 25% the damage so that Kyogre has always lots of life for Water Spam. Follow me to cash the damage of individual attacks and Helping Hand is a free +1 for bringing in the range of OHKO opponents double target.

 

[cityscapes]

Ok, got a few things for you.
First of all, you really should add more description. Why are you running 84 Speed on Rayquaza? How come your Kyogre doesn't have maximum Special Attack? Can Smeargle really stand against, say, a Double Edge from Kangaskhan?
Secondly, you only have one check to Ferrothorn with Overheat. Ferrothorn is a common problem for RayOgre teams and you will be seeing a lot of them. I'd suggest running something else with a Fire move (or at least a Fighting one).
Thirdly, how do you beat opposing Raichu and Thundurus? Thundurus especially seems like a problem because although Hidden Power Ice is uncommon, it still threatens both restricted legends you have; Clefairy and Smeargle hate Taunt and Scizor can't do anything except steal its Sitrus Berry.
I'd suggest adding something with Lightning Rod. Manectric looks like a good choice: It can threaten Ferrothorn with Flamethrower, take advantage of the rain with 100% accurate Thunder, provide a second Mega option for your team, protect Kyogre with said Mega option's Intimidate, and even beat Dragons with Hidden Power Ice!
I think you should replace Thundurus for Manectric and change Scizor for Crobat. Everyone really knows what Scizor does, and not only does it get walled by stuff like Salamence, it loses to both Primals, Overheat Mega Rayquaza, etc. while not damaging beasts like Kangaskhan enough to beat them either. Crobat, on the other hand, is much better at checking Xerneas and Smeargle with Taunt support, provides speed control with Tailwind which your team desperately needs, and makes an ideal partner for Mega Rayquaza, to top it off.
Try these sets:
Manectric @ Manectite
Ability: Lightning Rod
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature
-Protect
-Thunder
-Flamethrower
-Hidden Power [Water]/Hidden Power [Ice]
Crobat @ Lum Berry
Ability: Inner Focus
EVs: something like 252 HP / 172 Def / 84 SpD iirc
Careful (?) Nature
-Super Fang
-Tailwind
-Taunt
-Haze
Sorry about the Crobat set, I haven't really done my research on it :/
Anyway, thanks for reading!