Overall the team is nice, but there are a few things that you may need to reconsider.
This may get you 1400s, but after that, you may have some problems.
Problems in the team:
First thing I noticed was:
@Demon Hunter, I use one in case the other got knocked out or is in an unfavorable position to switch-in or Mega Evolve .
commented 4 hours ago by AlphaMew
Well, it doesn't work that way. If you have already Mega Evolved one Pokémon, no other Pokémon would be able to Mega Evo, even if your first Mega Evolved Mon is knocked out. Another thing is, a few moves and items are a little messed up. We would go through that in this RMT ;).
Other Team Archetypes against this Team:
Hyper Offense: HO vs. HO is fun, and sometimes you also have to think. Their Deoxys-Speed sets hazards, which pinch the Mega Rayquaza a lot, Life Orb Marshadow Shadow Sneak's the Ultra Necrozma, Close Combat's the Arceus, Sneak's the Mewtwo also, and leave the dealing with other Pokémon to their PDon and Mega Ray. Dual Screens lead also more or less would ruin you, as their Mega Rayquaza and Xerneas would setup like it's their birthday, etc.
Bulky Offense: Bulky Offense would deal with the Marshadow easily, and the Coil defensive forms of Zygarde's can also make nice setup fodder out of the Arceus. If they have multiple Defoggers, your PDon would have more and more pressure on it to set the Rocks, whereas things like Ho-Oh would also take care of NDM and Marsh. Otherwise, if the Ray gets a Dragon Dance under it's belt, you can aim for a late game sweep, but beware of Support Arceus formes, they bulky as.. Gods.. They are 2HKO'd by even a +0 Dragon Ascent, so go for a DAscent if you expect their switch-in's.
Balance: Mega Gengar's would revenge kill the Ultra Necro. And the same as BO, a few Defensive behemoths can really come mid-way of one of your sweeps. Ferrothorn's would be very difficult to deal with, especially when they get to know that the Marsh is Leftovers and doesn't have Close Combat...
Stall: Stall, you may faint a few mons, but then, Ho-Oh, hazards, and Will-O-Wisp is gonna cripple you. And things like Lugia can also phaze out loads of things that try to setup, while Defensive PDon would Toxic half the things here. As I mentioned before also, Will-O-Wisp and Sacred Fire would really cripple you, as 4 out of 5 of the attackers in your team (Don is defensive right?) are Physical, which would mean that Burns really would cripple you. Even the Mewtwo doesn't have Taunt...
Now, to the team:
1. Groudon-Primal: It's nice, SpDef PDon is great in checking a plethora of threats. It can tank a Focus Blast from a +2 Xerneas, and then retaliate with a Precipice Blades and all. I'll just tweak the EV's a little bit, so that it also becomes a little better on the Physically Defensive side:
Groudon-Primal @ Red Orb
Ability: Drought
EVs: 252 HP / 36 Def / 220 SpD
Careful Nature
- Stealth Rock
- Precipice Blades
- Roar
- Stone Edge
This set aims to be better off physically as well, it can survive a +1 Dragon Ascent from a Mega Rayquaza, and then phaze it out. Rocks is Rocks, PreBlades is nice STAB, Roar is great to phaze out foes who try to make some setup fodder out of the Don, Stone Edge hits Ho-Oh, Yveltal, etc for super-effective damage.
2. Rayquaza-Mega: Niicee. Don't change anything except for the nature. Make it Adamant, as it already outspeeds a nice amount of foes after a +1, and Adamant increases it's damage output to stellar levels. You can also opt for V-Create > Earthquake to hit Skarmory, but that's optional.
Updated set:
Rayquaza-Mega @ Life Orb
Ability: Delta Stream
EVs: 4 HP / 252 Atk / 252 Spe
Adamant Nature
- Dragon Dance
- Dragon Ascent
- Extreme Speed
- Earthquake
I think I won't have to explain it, but well, Dance is setup, Ascent is nice STAB and important to Mega Evo, ESpeed is to revenge kill and nice priority, Quake hits PDon and SteelCeus.
3. Marshadow: Nice but why Leftovers? I never expect mine to survive any nice hits, and well, it really won't ;-;. Use Life Orb, that increases your damage output to greatt levels. And also, why Drain Punch and Iron Head?? Defensive FairyCeus take something like 40% from Iron Head, and then OHKO you with Judgement. Niice, you say. Replace it with Pursuit, it helps to trap foes like Ultra Necro, boosted foes with + Attack who fear SpecThief (though don't rely on it), etc. Close Combat farr better than Drain Punch, it dishes out more damage.
Improved set:
Marshadow @ Life Orb
Ability: Technician
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Spectral Thief
- Close Combat
- Pursuit
- Shadow Sneak
Spectral Thief is Marshadow's preferred STAB move, giving it good coverage, allowing it to steal boosts, and going through Substitute. Shadow Sneak is a good priority option boosted by Technician, effectively receiving 90 Base Power after the boost from STAB and giving Marshadow the ability to revenge kill Mega Rayquaza. Close Combat is Marshadow's hardest-hitting STAB option, and with Life Orb, it allows Marshadow to OHKO many Pokemon that are weak to it. Pursuit allows Marshadow to trap Pokemon such as Mega Gengar, Lunala, and weakened foes, especially CM and SD Arc formes.
4. Mewtwo-Mega-Y: Second Mega uwu. There's a limit of one Mega per team if you aren't doing Mix And Megas. I'd say replace it (yes it's necessary) with Xerneas. Nice late-game / mid-game sweeps. It can also punch holes in the opposing team without Geomancy also, Moonblast is niice.
The set:
Xerneas @ Power Herb
Ability: Fairy Aura
EVs: 168 Def / 252 SpA / 88 Spe
Modest Nature
- Geomancy
- Moonblast
- Thunder
- Focus Blast
Geomancy turns Xerneas into a fast, powerful, and bulky special sweeper.
Moonblast gives Xerneas maximum damage output against neutral targets due to Fairy Aura and STAB boosts.
Thunder hits foes that resist Fairy-type moves such as Ho-Oh, Celesteela, and Toxapex, as well as the specially bulky Lugia and Primal Kyogre.
Focus Blast hits Primal Groudon, Ferrothorn, and most Steel-types such as Necrozma-DM, Magearna, and Bronzong for solid damage.
88 Speed EVs ensure that Xerneas outspeeds +1 Adamant Mega Salamence when boosted and Marshadow after a Geomancy boost and Sticky Web.
252 SpA maximises it's damage output, and the rest are dumped into Defense to survive the Physical attacks nicely.
5. Arceus: Shadow Force looks better on GhostCeus, not NormalCeus. Go for Shadow Claw, as, well, it's nice. Arceus finds itself a niche on offensive teams thanks to its access to a consistent and strong priority move in Extreme Speed. The move also helps with picking off faster weakened threats such as Geomancy Xerneas and Rock Polish Primal Groudon and preventing them from netting excessive damage on the team.
Improved set:
Arceus @ Chople Berry
Ability: Multitype
EVs: 236 HP / 252 Atk / 4 SpA / 16 Spe
Naughty Nature
- Swords Dance
- Extreme Speed
- Shadow Claw
- Ice Beam
Swords Dance boosts Arceus's rather mediocre damage output, allowing it to pick off on weakened teams late-game.
Extreme Speed lets Arceus outpace faster foes and Choice Scarf users and revenge kill the likes of Xerneas, Mega Mewtwo Y, and Naganadel.
Shadow Claw allows Arceus to hit Ghost-types such as Marshadow, both formes of Giratina, and Lunala super effectively, and this move is indispensable, since Arceus is easily checked by said foes otherwise.
Chople Berry allows Arceus to survive a Fighting-type attack from Marshadow and Mega Lucario, preventing them from easily revenge killing Arceus.
I went for Ice Beam as it doesn't let things like bulky Xyg with Coil to make nice setup fodder of the Arceus, and it also hit's things like Meg Mence. You can go for an alternate set of:
Arceus @ Chople Berry
Ability: Multitype
EVs: 240 HP / 252 Atk / 16 Spe
Adamant Nature
- Swords Dance
- Extreme Speed
- Shadow Claw
- Recover / Facade
Recover is handy when setting up against foes that do not have status moves or a way to 2HKO Arceus and can potentially allow Arceus to provide its team with extra security against Marshadow, which Arceus has to remain healthy to check with Chople Berry intact.
Facade is nice if you ever seem to get Toxic'd / Will-O'd, etc. It KO's a nice amount of things after a +2.
6. Necrozma-Dusk Mane: Nice, but I'll change the EV's and Nature; plus one move
Necrozma-Dusk Mane @ Ultranecrozium Z
Ability: Prism Armor
EVs: 28 HP / 220 Atk / 8 Def / 252 Spe
Jolly Nature
- Swords Dance
- Photon Geyser
- Earthquake
- Stone Edge
Photon Geyser hits foes like Ho-Oh and Water-types that Necrozma-DM cannot effectively hit with its conventional sets. It is notably capable of OHKOing Mega Gengar after Stealth Rock even when Necrozma-DM is burned.
Earthquake provides Ultra Necrozma with vital coverage against Primal Groudon and Steel-types.
Stone Edge breaks through problematic Flying-types like Yveltal and Lugia, as well as letting Ultra Necrozma better deal with Ho-Oh and Mega Salamence.
28 HP and 8 Defense EVs prevent Life Orb Marshadow from OHKOing Ultra Necrozma after it switches into Stealth Rock and allow Necrozma to check Geomancy Xerneas in its Dusk Mane forme.
Maximum Speed EVs with a Jolly nature allow Ultra Necrozma to take advantage of its high Speed tier, letting it outspeed all Arceus formes and Marshadow. The rest of the EVs are dumped to Attack to maximize Ultra Necrozma's damage output.
Final Team
Hope it helped!!
PS: Hyper Offense is a nice play style, but Balance is, in some aspects, better. Switching to Balance maybe better, but that's your choice ;)
