Pair 'o Hax

After playing around with Sun teams, Sand teams, and Rain teams, I summed up my two most favorite things: Thunder Wave and Shaymin-Sky form.
At first I thought I was simply getting lucky with this team, but after taking this team to a 19:3 win/loss record I thought I'd put it up for some comments. (One memorable loss went to Sweep, who explosioned my 2x SpA arceus-fighting with Genesect, so that his Arceus could extremespeed kill both it and my weakened Shaymin+Kyogre). This is not a gimmick team, and although Serene Grace flinching+paralyze makes a deadly combo the team almost never finishes with this.

But first things first, the team:

The team was based off the idea of parahaxing the opponent to death, so I started off with a lovely shaymin-s and kyogre (bulky paralyzer). Hoping that the opponent's scarfers would all be paralyzed late game, I made the choice of using a deoxys-a as an actual dedicated attacker. Mew was originally a dual screener but t-wave and offensive baton passing was so much nicer. Arceus fighting is quite underused in my opinion, but he checks darkrai quite nicely, also ice beams groudon which cannot be t-waved. Groudon was added as an afterthought, but he has got to be the best thing that ever happened to me, as you'll see later.

Shaymin-S @ Leftovers
Trait: Serene Grace
EVs: 124 Hp/ 132 SpD / 252 Spe
Calm Nature (+SpD/-Atk)
- Air Slash
- Seed Flare
- Substitute
- Leech Seed

The moveset is quite standard for troll shaymin (lovingly called Flying Fucker), but the EV's are probably debatable. Rather than offensive, shaymin has special bulk enough to switch in on a single attack (scarf palkia anyone?). The lack of positive speed nature means late game Darkrai/opposing Shaymin will outspeed and ruin this guy (unless paralyzed), but once Shaymin gets a sub up he'll parahax the opponent to death.

Kyogre @ Leftovers
Trait: Drizzle
EVs: 252 Hp/ 252 SpD/ 4 Spe
Calm Nature (+SpD/-Atk)
-Ice Beam
-Thunder Wave

The bulkiest specially defensive spread Kyogre can run, with all his coverage moves and a nasty t-wave. I don't see too many spreads like this, but with Kyogre I'd much rather prefer bulk than offense. He out paces scarf Kyogre with t-wave, then kills with thunder. Groudon dies to 2 ice beams (3 if bulky, but then he'll waste a turn with srocks or something). If you need to sac something for a free switch, Kyogre is usually the first thing to look to-the team isn't based around rain and he'll never be a sweeper.

Deoxys-Attack @ Life Orb
Trait: Pressure
EVs: 4 Def/ 252 SpA/ 252 Spe
Modest Nature (+SpA/-Atk)
-Ice Beam
-Dark Pulse
-Psycho Boost

I have to admit I pulled this entire set out of my ass; but tbh, I really don't see why nobody uses Deoxys-A the way he's supposed to be used: the fastest, deadliest beater and you feel no guilt when someone OHKOs him. Life Orb means we can pull him out late game when the opponent set up srocks (because he's not sashed), and considering he dies to every move in the game (even extremespeed Dratini, true story), the life loss is of no importance. Nobody expects Deoxys to OHKO Mewtwo with Dark Pulse, nobody expects Deoxys to OHKO Kyogre with Thunder, but this baby does all that. I'd save him for mid-late game, when the scarfers are all paralyzed. Oh, you'll also be switching him out a lot to Rayquazas and Arceus Normals, because those extremespeeds will blow you out of the sky. But with half the team running the bulkiest spreads possible, switching out shouldn't be too much of a problem.
The 4 EVs in defense is so that Genesect gets a boost in SpA, and when he (hopefully) uses U-turn you switch to Kyogre who takes it like a champ.

Mew @ Lum Berry
Trait: Synchronize
EVs: 252 Hp/ 156 Def/ 100 SpD
Bold Nature (+Def/-Atk)
-Baton Pass
-Nasty Plot
I'm considering maximizing EVs in Def since there's so many bulky special walls on this team, but Mew has to deal with Darkrai a lot so I'm not sure. Speaking of Darkrai, Mew is such a good lead against it. Turn 1 Darkrai puts Mew to sleep (lum berry), Mew T-waves Darkrai. Turn 2 Mew Subs since he's now faster, and Darkrai's second Dark Void fails. Proceed to Nasty Plot+pass to arceus. If they dark pulse instead... well hopefully you tank one of them in time to t-wave, then switch to Kyogre or something. Aside from leading against Darkrai, Mew is more of a late game baton passer to Arceus. Many a game has been won in that fashion.

Arceus-Fighting @ Fist Plate
Trait: Multitype
EVs: 100 Hp/ 252 SpA/ 152 SpD/ 4 Spe
Calm Nature (+SpD/-Atk)
-Ice Beam
Speaking of Arceus... Here is part 2 of Darkrai checking. If Darkrai puts something to sleep, switch Arceus in and he's done for. In game Arceus is nicknamed Arceus-Rock, but it's not like that's fooling anybody. Originally Arceus was a lot bulkier, but fearing Groudon I invested in SpA so that Ice Beam could seriously maim it. Scarfers usually can't handle Arceus as T-wave, recover, and judgement really destroy them (aside from Mewtwo). If Deoxys and Shaymin are in pristine condition, Arceus can go down simply t-waving as many things as possible. Otherwise, save Arceus as a late game sweeper (also save him if the opponent looks like he's saving an extreme-killer arceus).

Groudon @ Leftovers
Trait: Drought
EVs: 252 Hp/252 Def/ 4 SpD
Impish Nature (+Def/ -SpA)
-Stone Edge
I'd like to name Groudon (Mac DaddY) MVP of the team, often wrecking half the opponents team before he goes down. Groudon is the most common lead for this team, and he kicks ass. Deoxys-S's waste a turn taunting Groudon (we 2HKO with EQ), and scarfers are scarred for life with T-wave (besides Genesect, where we instead switch to Kyogre fearing that boosted Ice Beam). Sun teams are the funniest, since Groudon lures out so many Ho-ohs (hence Mac Daddy cuz he gets all them hohoes). Stealth Rocks would be nice, but I've decided a guaranteed OHKO even without attack investment is well worth it. 4x damage with Stone Edge stops all Ho-ohs, period. Lots of opponents try to set up on Groudon, but thunder wave -> roar is such a great combo. The one I fear most is Calm Mind Ice Beam Mewtwo, but for some reason nobody's used it yet. If you don't lead with him, save Groudon for end game Extreme Killer Arceus, since he eats 3x Arceus's extreme speed all day long. (Actually, he takes one of them and then roars, because otherwise he dies.)

Using the Team
If the opponent has a Darkrai, usually lead with Mew; otherwise use Groudon. Kyogre is also cool. With 2/3's of the team using t-wave, there isn't too much investment in speed, so early game will definitely be a deciding factor. Optimally, you'll be t-waving and roaring through the opponent's team with Groudon, killing the few things you can (Deoxys, Tyranitar, Ho-oh, Volcarona). Most people underestimate Groudon's immense bulk; as a lead he could very well visit 2/3 of the opponent's team before he dies. If the opponent hurts him irrevocably (crit hax, stupid plays), never fear! Kyogre is there as backup. As mentioned earlier, Kyogre really isn't a core part of the strategy. He thunderwaves stuff and tanks through special attacks. Mostly Kyogre is a pivot, since the rest of the team always has an enemy to watch out for, where you'd much rather have Kyogre take the hit. Shaymin watches out for Ice beam, Arceus fears Mewtwo, Groudon fears special attackers, Mew fears most sweepers, Deoxys fears essentially everything it can't OHKO.
Mid and late game vary depending on the team you're fighting. If the opponent is stall-based, save Shaymin as sub-leech seed-paraflinch is great. Against hard sweepers, you have to focus on t-waving them. If the whole team is t-waved and extremespeed arceus/rayquaza do not exist, Deoxys Attack will have a very nice sweep. Either way, Mew is important late game as baton passing a sub+2x SpA is more viable than you'd think when they're paralyzed. If you have a chance to pull anything off, this is the game ender. Stall teams fear a nasty plotted Shaymin, and Sweep teams fear a nasty plotted Arceus. The latter is actually the better option, since Recover is more reliable than leech seed for hp recovery.

Common threats checklist:
-Scarfers in general are put out of action by t-wave (yet to see scarf Groudon). This team's Kyogre/Groudon core checks pretty much any scarfer. Arceus is also bulky enough to handle most scarfers.
-Specs users can be a problem, but since most teams rarely use more than one it's safe to sacrfice Kyogre to paralyze them. Banded users are entirely handed by Groudon.
-With Sleep Clause back in (praise the lord), Arceus ruins Darkrai once it puts something else to sleep. Remember if you have a free switch to Mew that Mew is also an amazing check.
-Swords Dance Arceus is a threat to all teams-status+leech seeding it early is great. If it gets multiple boosts in, wait for it to kill something, then switch into Arceus (judgement) or Groudon (roar)
-Mew sets up with ease in front of Giritina and Lugia. Phazing is a bit of a problem, but Shaymin's parahax+leech seed is great for handling them.
Like all teams, using this one effectively takes skill and prediction. Please give the team a shot before claiming it stupid... when I first looked at this team I thought "wtf was I thinking" but it's turned out to be much better than I thought.
Hi there nice team,

A few suggestions I have though... First off I think your a little too focused on Darkrai. Consedring you have mew and fighting arceus. This being said you could edit arceus to ghost arceus letting you check normal arceus with swords dance easier. Or you could change it to normal arceus with a more offensive build. Speaking of defense the team is just that. But Deoxys is way out of place. I can see wanting some muscle but Mewtwo is more bulky and can even take a special rend from scarf palkia. Plus Mewtwo is a hard hitter two and is probably better. But if you want Deoxys I would recommend extreme speed or superpower letting you take advantage of its great attack stat as well. Also Consedring you have no entry hazards I don't think roar on groundon is necessary. I would run stealth rocks on groundon. Last but not least you might want to invest a little more in shymins spa eves. But overall cool concept and team.

Blue Jay

The notorious Good Wife
is a Contributor Alumnus
This looks like a really cool (and extremely annoying) team. I definitely like that it doesn't quite fit into the standard playstyles and uses some rarer sets/Pokemon. As for you wondering about Deoxys-A, it quite simply tends to underperform on a lot of teams, but spreading paralysis definitely patches up half its problems, namely that almost any team uses Pokemon that can outspeed it without priority (and OHKO because lol).

As far as advice goes, I quite firmly believe that every team should carry Stealth Rock. It can be used by so many generally great Pokemon, and brings so many benefits at such a low cost.

I also believe that Arceus-Fighting would be more efficient with Calm Mind over Thunder Wave. I know that's the general theme, but with Calm Mind, all that Special Defense investment could go elsewhere, and Arceus would be more self-sufficient and flexible. At which point you could also consider replacing Mew. I feel like Dialga would be a worthy addition; great defensive typing, it can use Thunder Wave (yay), give you Stealth Rock, phaze more (you seemed to appreciate that, and Stealth Rock makes phazing a lot better) and blast frailer stuff with Draco Meteor. Ferrothorn would also do well; it also provides paralysis and SR support, but is also a great help against opposing Kyogre among other Pokemon with Leech Seed+Power Whip.

Also, one of the most concerning weaknesses in your team is that it is quite vulnerable to entry hazards. Most of your team is quite weak to entry hazards, you lack reliable recovery to deal with the damage caused and you have little to prevent entry hazards going up. Consider using a spinner, as a solid stall team could stack hazards against you and then shuffle your team about until it is all but dead (Thunder Wave or the mediocre attacks most your team can muster will do little to it).