Doubles Ubers? My favorite.
Okay, so obviously you can't really go wrong with just slapping on a bunch of non-dragon ubers with 252/252 spreads, but you are a bit xern weak and you're missing protect, the most important move in the game.
Protect is really important in all doubles format for a lot of reasons. The most easily understood one is for stalling out fake out, tailwind, trick room turns, and even opposing protects. The most important reason, though, is that you can predict and take advantage of double targets, preserve valuable threats, or even take guaranteed turn advantages by altering speed order. A classic example for your team would be:
Your +2 30% xerneas + mega ray vs. opposing espeed arceus and primal groudon. Without protect, the arceus would easily pick off your xern with espeed or at least force a switch. If you protect xern, though, the matchup turns into ray vs arceus+pdon. The arceus wastes a turn attacking into xern's protect, your ray gets an opportunity to ko the arceus, and the opposing pdon can't kill your ray. This alters the turn order, so the fastest mon ends up wasting its turn and your slower mon gets a chance to remove it. Of course, the opponent could predict your protect on xern and protect with their arceus, stalling out your protect turn. This creates an uncertainty depending on prediction, but being able to predict is what a lot of players call "skill."
Since your team is setup oriented, there are also a few cool techs you can use with protect. In an unboosted xern+pogre situation, which I imagine you'll lead quite often, the opponent might double target the xerneas to prevent the setup. If you protect with xern, ogre might be able to kill something off or even just switch out to something with a more favorable matchup. Even after you get +2, the opponent will really focus attacks on xern in an attempt to remove it, so you can protect xern while psyching up with ogre (psych up goes through protect), practically winning the game.
Have I convinced you yet? Use protect>brick break and shadow force>shadow claw on arceus, protect>swords dance on groudon, protect>dragon claw on rayquaza, protect>thunder on kyogre, protect>flash cannon on xern.
As I said before, you're quite weak to xerneas, so I suggest using ho-oh or jirachi in place of yveltal. Ho-oh plays similarly to yveltal as a bulky offensive tailwind setter, while jirachi turns into a full support with follow me/thunder wave+iron head. Either works, you just need a second xerneas wall besides groudon.
Ho-oh @ Life Orb
Ability: Regenerator
EVs: 252 HP / 252 Atk / 4 Spe
Adamant Nature
- Brave Bird
- Sacred Fire
- Tailwind
- Protect
Jirachi @ Metal Coat
Ability: Serene Grace
EVs: 252 HP / 96 Def / 124 SpD / 36 Spe
Impish Nature
- Follow Me
- Iron Head
- Thunder Wave
- Protect
Outside of that, consider running a bulkier xerneas spread. You really don't need that much speed or spa investment when it gets boosted so high. Modest 252 HP / 160 Def / 92 SpA / 4 Spe will live ray's combined dragon ascent and espeed, take a 3hko from precipice blades, and has the rest invested in spa.
Hope you have fun with the team! Really though, protect is what makes doubles beautiful, you should try it out.
