This team may work in the lower ladder, but not up high.
Let's start from the start, shall we?
1. Groudon-Primal: Precicpice Blades and Rocks are good. Go with them. I don't understand Fire Blast and Thunderbolt. If Thunderbolt is there for P-Kyogre coverage, just go with Solar Beam, does more damage. Fire Blast, no, don't use it. It's very much unreliable, with 85 Accuracy, and just 8 PP. Defensive Pokemon's such as Giratina-O completely wall this set, and then they can cripple you with their Toxic. Don't go for a mixed set, it won't really help against Mega Ray's also. Use this set, probably better:
Groudon-Primal @ Red Orb
Adamant Nature
Ability: Desolate Land
EVs: 104 HP / 202 Atk / 52 SpD / 152 Spe
- Stealth Rock
- Fire Punch
- Precipice Blades
- Stone Edge
104 HP is to avoid a chance to get KO'd by a +1 Soul Stealing Seven Star Strike. 52 SpD to avoid the KO from a +2 Modest Xerneas Focus Blast. Rest of the EVs go into Speed and Attack. You can also use an alternate, and a simpler, spread of 252 Atk / 4 Spd / 252 Spe with Adamant Nature to maximise damage output, but the defence drops are noticeable. Precipice Blades got a very high chance to OHKO Primal Kyogre's after Stealth Rock damage (202+ Atk Groudon-Primal Precipice Blades vs. 0 HP / 4 Def Kyogre-Primal: 291-343 (85.3 - 100.5%) -- 81.3% chance to OHKO after Stealth Rock), but as Kyogre-Primal's outspeed you even with a Modest Nature, don't be reckless and attack only when you switch in after the Kyogre, so as to get Desolate Land activated and then it won't be able to Water Spout or Origin Pulse you.
2. Toxtricity: Ehh. This Pokemon also sees very less usage in OU, let's forget AG. Utilise a Defogger, as Hazards will wear down your team gradually. Yvel is great, especially with HDB. The set:
Yveltal @ Heavy-Duty Boots
Ability: Dark Aura
EVs: 252 HP / 4 Def / 252 SpD
Careful Nature
- Knock Off / Snarl
- U-turn
- Defog
- Roost
This is more or less a Cal-S check. Knock Off is to remove items, Snarl to lower SpA, U-Turn for pivoting, Defog for hazards, and Roost is reliable recovery.
3. Feraligatr: If you want a good match, don't use this. Please. It's like mediocre. Plez. A far-better Water Type would be Kyogre-Primal, pretty much obviously. I don't think I really need to explain it, and so here's a set that I used:
Kyogre @ Blue Orb
Ability: Drizzle
EVs: 4 Def / 252 SpA / 252 Spe
Modest Nature
- Water Spout
- Thunder
- Origin Pulse
- Ice Beam
Modest or Timid Nature both work, it's upon ya. Water Spout hits like a real truck with 180 base SpA and Heavy Rain to complement it. Another good water type may be a Kyogre (not Primal) x_x. This one is Scarfed, which means it outspeeds like almost the whole unboosted tier and gives them a Water Spout straight. on. the. face. The set:
Kyogre @ Choice Scarf
Ability: Drizzle
EVs: 4 Def / 252 SpA / 252 Spe
Modest Nature
- Water Spout
- Thunder
- Origin Pulse
- Ice Beam
It's totally the same, just the item diffrence, so, yeah, it's not bad to use. A few Calcs.. (252 SpA Kyogre Water Spout (150 BP) vs. 4 HP / 0 SpD Zacian-Crowned in Rain: 364-429 (111.6 - 131.5%) -- guaranteed OHKO) (252 SpA Kyogre Water Spout (150 BP) vs. 0 HP / 0 SpD Xerneas in Rain: 415-490 (105.5 - 124.6%) -- guaranteed OHKO). Use this IF you can cope with not being able to change moves and all, otherwise, Primal Kyogre rocks.
4. Corviknight: Ok so, this is like hitting an axe on your own leg. (252+ Atk Life Orb Rayquaza-Mega V-create vs. 252 HP / 252+ Def Corviknight: 499-588 (124.7 - 147%) -- guaranteed OHKO). Use a Defensive NDM as a Rocks setter, as it's also a good Zac-C check:
Necrozma-Dusk Mane @ Rocky Helmet
Ability: Prism Armor
EVs: 252 HP / 252 Def / 4 SpD
Impish Nature
- Stealth Rock
- Sunsteel Strike
- Morning Sun
- Knock Off / Toxic
Rocks is hazard, SStrike good STAB, Morning Sun recovery, and last move is your choice; Knock removes items, Toxic cripples said switch-in's like Cal-S.
5. Gallade-Mega: Just use a Mega Ray, plez. this thing too much underrated, it's UUBL. Even if you keep using it, replace Poison Jab with Swords Dance, and Throat Chop with Knock Off. A sample Mega Ray set:
Rayquaza @ Life Orb
Ability: Air Lock
EVs: 252 Atk / 4 Def / 252 Spe
Adamant Nature
- Dragon Ascent
- Dragon Dance
- Extreme Speed
- Earthquake / V-Create
Too OP. Very much OP. It seriously sweeps. Ascent is for Mega Evo, Dance is setup, ESpeed is to revenge kill weaker foes, plus a good priority, Quake hit's PDon's, Zac-C, NDM, SteelCeus, while V-Create also hits the Pokémon mentioned before, it has the benefit of hitting Skarmory and Celesteela.
6. Serperior: Well, I don't know how this fares in Gen8 NatDex, in Gen7 OU, it’s pretty good. Go for Zac-C, it's good. The set:
Zacian-Crowned @ Rusted Sword
Ability: Intrepid Sword
EVs: 4 HP / 252 Atk / 252 Spe
Adamant Nature
- Behemoth Blade
- Wild Charge
- Close Combat
- Assurance
BehBlade STAB, WCharge for POgre's, as well as Ho-Oh's. Close Combat is more or less to hit NDM, plus Ferrothorn's. Assurance is for NDM's.
Final Team
All's most probably great now, hope I helped :3
