The team kinda needs a rework tbh. A few of the Pokémon and Move choices are you quite questionable. I'll try to help you a little here.
Gengar-Mega:
oooooooo I'm seeing a nice new set after a looong time!! But, even though it maybe creative, it won't really work. It's Imposter-proofed, which is a very nice thing, but extremely common Pokémon, such as Safety Goggles Prankster-Haze Yveltal AND Wonder Guard's, just end its life. Unburden isn't a good ability. The set will be infinitely walled by Scizor-M, Arceus, Swampert-M, etc. After your opponent gets to know what coverage you have (through Imposter usually), they send in the correct WG and boom ggwp. You'll have to switch out, which means bye to the Unburden boosts. Therefore, I'll recommend Mold Breaker / Normalize > Unburden. Both sets have their own viability, but according to what I have in mind for the team, Mold Breaker would fit better here.
Gengar-Mega @ Spooky Plate
Ability: Teravolt
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Judgement
- Shell Smash
- Spore / Dark Void
- Secret Sword
Judgement + Spooky Plate is the best STAB combo for Gar-M. Shell Smash is the required more for setup. It's replaceable with Quiver Dance, but Quiver is such a niche option, I won't really recommend it. Spore or Dark Void is a choice, Spore is a better accuracy move, but fails to go past Safety Goggles and Grass- types, the former of which is very common. Dark Void does the same thing and also can touch almost everything, but has a worse accuracy.
Secret Sword hits everything that Judgement doesn't, including Arceus formes (keep in mind that most Arceus are Normal- type, no matter what the preview says, an Arceus can be any other type only when it's Ability is Multitype and it's holding a Plate. And those are not too common). It's also Improofed, as non-Plate'd Imposters won't be able to touch it. Genius set tbh.
Rayquaza-Mega --> Aerodactyl-Mega
Even though Contrary looks appeasing, it's not that good. With all the Haze users running around, Contrary is outclassed heavily by Mold Breaker. But here, I'll recommend Aerodactyl-Mega > Rayquaza-Mega, because tbh Gar-M does the role of a special breaker (I don't like Physical Ray).
Mold Breaker Aero-M has got very limited switch-in's, as Band Dragon Ascent + Thousand Arrows have almost unresisted coverage. It can also force momentum with U-Turn, which helps a lot. It also has an extremely high speed tier, which means that it out speeds almost the whole unboosted metagame. Also, if you’re running Choice Band, it makes the Aero a TrickChoice Pokémon, which are so irritating..
These types of monsters could be a major burden to any team, especially to defensive Wonder Guards. They come unexpected with a Choice Scarf, Choice Band, or Choice Specs and use Trick to give it to the opposing Pokemon. Oftentimes they can make use of the choice item but make sure the Pokemon it's tricking the item into can't. It's heavily advised that you're careful around any Pokemon you suspect to be carrying a choice item. The move Knock Off and the item Mail are the best ways to take care of this threat, but respective Mega Stones and Griseous Orb can also do the trick.
Source
It becomes a burden on the opposing team anyways, so another plus point. If you play carefully around it, it can seal a match.
Now we dive into the set..
Aerodactyl-Mega @ Choice Band
Ability: Teravolt
Jolly Nature
EVs: 252 Atk / 4 Def / 252 Spe
- Dragon Ascent
- Diamond Storm
- U-Turn
- Thousand Arrows
Another genius set. Ascent is the main STAB that you can spam (be aware of the low PP though), hits very very hard with Band, in the end only Aggron + King's Shield Mega SlowBro can stop it. Diamond Storm is another nice STAB that you can click when in doubt. U-Turn is mandatory for the pivoting benefits, and TArrows nail Electric- Ballon WG's, and Steel- types which resist Aero's STAB combo. With Teravolt, you hit each and every WG, so no need to worry (much).
Manectric-Mega
I don't understand why you're keeping Toxic for SturdNinja's when you already have Gastro Acid. Even though Toxic is a nice move on it, we'll swap it for Taunt here, because random WG's like Audino-M etc just sit on the team.
Manectric-M is a nice Wonder Guard abuser for it has zero weaknesses with Air Balloon + Electric typing, and on HO Teams, it indeed is a good Wonder Guard pick, often the only Defensive-oriented Pokémon on Hyper Offense. Electric- as a sole typing can be useful also, as it resists Dragon Ascent and Aeroblast. Manectric's speed tier is also quite good, as it outspeeds non-Scarf Gar-M, MMX, and everything below.
Manectric-Mega @ Air Balloon
Ability: Wonder Guard
EVs: 248 HP / 8 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Volt Switch
- Gastro Acid
- Taunt
- Heal Order
Rather than a Electric- STAB like Discharge, I went for Volt Switch here mainly because it provides the team with momentum. Gastro Acid is mandatory, as it suppresses Wonder Guard and other abilities (including Sturdy of Shedinja's). Taunt is mainly for the defensive WG's which can set their hazards / anything else. As the Pokémom suffer from 4MS, they usually carry four status moves, and so you'll be okay with Taunt. Heal Order is to heal yourself.
Arceus --> Diancie-Mega
Arceus does nothing here. Weakness Policy + Parting Shot never work; you lose your boosts after you click Parting which'll make you sad. I'm adding Diancie-M here, as it provides support against Deo-S, plus is one of the best FakeSpeed users in PH
Pixilate Fake Out + Extreme Speed hit's everything that doesn't resist it hard. It also functions as a way to revenge kill threatening setup sweepers such as Gyarados-M (for which you should always prep). Diancie-M can also act as a hazard setter, which it does beautifully, because of the number of switches it forces.
Diancie-Mega @ Focus Sash
Ability: Pixilate
EVs: 252 Atk / 4 SpA / 252 Spe
Naughty Nature
- Fake Out
- Extreme Speed
- Searing Shot
- Toxic Spikes
FakeSpeed is mano. Searing Shot is for the Steel- types, especially WG Scizor, which we won’t be able to hit otherwise. I went for Toxic Spikes > Stealth Rock as the last move, because on HO Toxic Spikes really shine; it’s an indirect way to damage Wonder Guard’s and all, so it’s quite neat. Item can be Pixie Plate also, but Sash is better here as we aren’t running Boomburst.
Groudon-Primal --> Blissey
Huge Power Groudon is outclassed by Mold Breaker and Shadow Tag Groudon, which are quite better than HP. And Passho Berry does nothing significant; Water- type coverage is extremely rare (unless you ladder with full force and meet a CTeam).
Now as the team is quite weak to offensive Mold's, we'll keep something that keeps those in check: Blissey. Imposter Blissey is meta defining, you need to make your sets Imposter proof (also called Improofed), otherwise you may get swept with your own incarnation. With Blissey's sky high HP stat, taking it down would be a real headache.
Blissey (F) @ Iron Plate
Ability: Imposter
Happiness: 128
EVs: 248 HP / 252 Def / 4 SpD
Impish Nature
- Transform
- Fake Out
- Whirlwind
- Wish
The set speaks for itself! I went for 128 Happiness as you never know when you're gonna encounter a max-Happiness Regigigas. As for the item, I chose Iron Plate because that makes Judgement Steel- type, which means that we hit opposing WG Xerneas super-effectively, and opposing Gengar-M won't be Improofed. Spooky Plate is another option but I prefer Iron Plate as we hit Xerneas (which can 6-0 us if it gets the opportunity to setup).
Moves are nothing significant.
Mewtwo-Mega-X
Why Parental Bond? That's a meme actually, Huge Power hit's far harder than it, and doesn't even trigger the extra damage from Helmet.
Mega Evolved Pokemon were proven to be great in ORAS and Mewtwo was not an exception. During the 2012-2014 metagame Mega Mewtwo X has proven to be the most successful breaker with its Attack and Speed stats each being within a 97-100 percentile and access to Huge Power/ Pure Power. Having the best physical offense stat combination in the game and an ability doubling its physical attack allows the Pokemon to run a wide variety of coverage moves the majority of Pokemon would be unable to deal with by themselves
The above text explicitly states that MMX is the best abuser of Huge Power, and denying it that would be quite meh. With the limited amount of checks for it, the opponent may have to do Sack Go Brr, which is a very hot point.
Mewtwo-Mega-X @ Safety Goggles
Ability: Huge Power
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Gear Grind
- Sacred Fire
- Fusion Bolt
- Play Rough
Standard set with the maximum coverage. It's also Improofed as Manectric-M walls it endlessly. I refrained from choosing any STAB option because that'll compromise its coverage, which we don't want. Plus Psychic- STAB is pretty trash rn. Chose the item as Goggles to catch Prankster Tina of guard and Play Rough them before they could Spore you.
Final Team
Hope it helped!!
