OU Cores

By NotFalse. Art by LifeisDANK.
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OU Cores


With ORAS OU being such an expansive tier with so many different Pokémon to choose from, teambuilding can sometimes be difficult. Cores are often a good way to begin building a team. Having a solid defensive backbone is the key to success for many balance teams, and a solid offensive core can be the key to success for many more offensively inclined teams. This article will break down some of the most popular defensive and offensive cores to date in ORAS OU to see how they function and why they are so effective.

Defensive Cores

  • Venusaur-Mega
  • Venusaurite Venusaur @ Venusaurite
  • Ability: Chlorophyll
  • EVs: 248 HP / 152 Def / 88 SpD / 20 Spe
  • Bold Nature
  • - Giga Drain
  • - Sludge Bomb
  • - Hidden Power Fire
  • - Synthesis
  • Heatran
  • Leftovers Heatran @ Leftovers
  • Ability: Flash Fire
  • EVs: 248 HP / 4 Def / 4 SpD / 252 Spe
  • Timid Nature
  • - Magma Storm / Lava Plume
  • - Earth Power / Stealth Rock
  • - Taunt
  • - Toxic

Despite how simple VenuTran is in theory, it remains one of the most popular and effective defensive backbones for a variety of team styles, ranging from bulky offense to stall. Based around type synergy, Mega Venusaur and Heatran cover each other's weaknesses almost flawlessly, with Heatran covering Mega Venusaur's weaknesses to Flying and Psychic, and Mega Venusaur dealing with Heatran's weakness to Water and Fighting in return. The only weakness that isn't covered is Heatran's weakness to Ground.

Whilst type synergy does allow this core to handle most Pokémon, it certainly doesn't deal with everything. Pokémon such as Mega Medicham and Kyurem-B are good examples of Pokémon that can break through this core. Mega Medicham's STAB combination allows it to hit both Mega Venusaur and Heatran super effectively, whereas Kyurem-B's Earth Power hits Heatran 4x super effectively, and its Teravolt ability allows it to circumvent Mega Venusaur's Thick Fat and hit it super effectively with STAB Ice Beam.

  • Latias-Mega
  • Latiasite Latias (F) @ Latiasite
  • Ability: Levitate
  • EVs: 248 HP / 8 Def / 252 Spe
  • Timid Nature
  • - Thunderbolt
  • - Ice Beam
  • - Thunder Wave / Reflect Type
  • - Recover
  • Keldeo
  • Leftovers Keldeo-Resolute @ Leftovers
  • Ability: Justified
  • EVs: 56 HP / 200 SpA / 252 Spe
  • Timid Nature
  • - Secret Sword
  • - Scald
  • - Sleep Talk
  • - Rest

The combination of bulk, Speed, and an expansive movepool has allowed Mega Latias to establish itself as one of the top-tier defensive Pokémon in ORAS OU. An effective blanket check to a large portion of the ORAS OU metagame, Mega Latias reliably checks many powerful wallbreakers such as Keldeo, Mega Charizard Y, Thundurus, and Manaphy. Whilst Keldeo may seem like a strange partner choice for a defensive core, as it is most notable for offensive sets, such as Choice Specs and Choice Scarf ones, its RestTalk set has surprising defensive utility and synergises well with Mega Latias.

RestTalk Keldeo boasts the ability to reliably deal with many Dark- and Steel-type Pokémon that can cause trouble for Mega Latias, such as Bisharp, Tyranitar, Weavile, Mega Scizor, and Heatran. In return Mega Latias covers Keldeo's weakness to Electric-types like Mega Manectric, Thundurus, and Raikou, and Grass-types like Mega Venusaur and Celebi. However, with both components of this core possessing a weakness to Fairy-types, Pokémon such as Clefable, Mega Altaria, and Mega Diancie can be some of the more problematic Pokémon to deal with.

  • Sableye-Mega
  • Sablenite Sableye @ Sablenite
  • Ability: Prankster
  • EVs: 248 HP / 160 Def / 96 SpD / 4 Spe
  • Careful Nature
  • - Knock Off
  • - Fake Out / Foul Play
  • - Will-O-Wisp
  • - Recover
  • Talonflame
  • Leftovers Talonflame @ Leftovers
  • Ability: Gale Wings
  • EVs: 248 HP / 252 SpD / 8 Spe
  • Careful Nature
  • - Brave Bird
  • - Will-O-Wisp / Taunt
  • - Bulk Up / Taunt
  • - Roost

With Mega Sableye being a new addition to ORAS, this is probably the newest of all the defensive cores on this list. The initial synergy here is obvious: Mega Sableye's Magic Bounce keeps Stealth Rock off the field for Talonflame, and in return Talonflame deals with the Fairy types such as Clefable, Sylveon, and Mega Gardevoir. However, the synergy goes much deeper than that. This core thrives on being able to spread status via Will-O-Wisp and aims to slowly wear Pokémon down via passive damage. Mega Sableye's Knock Off helps to further facilitate this notion by removing items such as Leftovers or Black Sludge. Mega Sableye's ability to remove these items can be a major key to the success of this core as many Pokémon such as Heatran, Landorus-T, and even Rotom-W utilize passive recovery as their only means of regaining HP. Once this has been removed, they are worn down much more quickly by passive damage, whether that be entry hazards, status or simply switching into attacks.

As you could imagine with a core that aims to spread damage through Will-O-Wisp, this core tends to struggle against Fire-types. Pokémon such as Heatran and Mega Charizard X can pose huge problems for this core, as not only are they immune to Will-O-Wisp, but they all have means to pressure this core. Heatran pressures Talonflame with Toxic or Stone Edge and threatens Mega Sableye with Lava Plume burns. Neither Mega Sableye or Talonflame can safely switch into Mega Charizard X.

  • Garchomp
  • Rocky Helmet Garchomp @ Rocky Helmet
  • Ability: Rough Skin
  • EVs: 240 HP / 176 Def / 92 Spe
  • Impish Nature
  • - Dragon Tail
  • - Earthquake
  • - Fire Blast
  • - Stealth Rock
  • Skarmory
  • Leftovers Skarmory @ Leftovers
  • Ability: Sturdy
  • EVs: 252 HP / 4 Def / 252 SpD
  • Careful Nature
  • - Iron Head
  • - Whirlwind
  • - Spikes
  • - Roost

This is a common hazard-stacking core seen on bulky offense, balance, or semistall teams. Both Garchomp and Skamory make use of their flagship ORAS sets, as this core pairs the ever-popular Tank Garchomp with Specially Defensive Skarmory. Both Pokémon in this core possess moves that phaze the foe: Garchomp with Dragon Tail, and Skarmory with Whirlwind. This phazing utility, combined with both Pokémon being able to set hazards reliably makes this one of the most effective hazard stacking cores that ORAS has to offer.

As far as defensive synergy is concerned, Garchomp's Ground and Dragon typing brings key resistances that allow it to check powerful Fire- and Electric-types for Skarmory. In return, Skarmory covers Garchomp's weakness to Fairy and Dragon, whilst also providing a reliable Ground immunity, so the core doesn't get run over by Pokémon such as Landorus-T or opposing Garchomp. Skarmory's Special Defense investment is also pivotal in many matches. Due to Garchomp's susceptibility to powerful special attackers, it also appreciate's Specially Defensive Skarmory's ability to check Pokémon such as Gengar and Alakazam. In return, Garchomp helps Skarmory against Swords Dance sweepers such as Bisharp and Mega Scizor, which can boost up and take advantage of Skarmory's uninvested Defense stat.

The majority of the threats to this core are Pokémon that have the capability to hit both Garchomp and Skarmory super effectively. Garchomp's 4x weakness to Ice and Skarmory's weakness to Electric means that this core's biggest weakness is to Pokémon with BoltBeam (Electric + Ice) coverage, such as Thundurus, Mega Manectric, Kyurem-B, Mega Latias, and Starmie. Other Pokémon such as Thunderbolt Latios, Hidden Power Fire Serperior, and Dragon Dance Mega Charizard X carry alternate super effective coverage and work in a similar vein.

Offensive Cores

  • Altaria-Mega
  • Altarianite Altaria @ Altarianite
  • Ability: Natural Cure
  • EVs: 252 Atk / 4 Def / 252 Spe
  • Adamant Nature
  • - Return
  • - Earthquake
  • - Dragon Dance
  • - Roost
  • Magnezone
  • Choice Specs Magnezone @ Choice Specs
  • Ability: Magnet Pull
  • EVs: 128 HP / 252 SpA / 128 Spe
  • Modest Nature
  • - Thunderbolt
  • - Flash Cannon
  • - Volt Switch
  • - Hidden Power Fire

Even with Mega Altaria's recent usage lull, AltZone is still a popular enough offensive core in ORAS to warrant a place on this list. A simple core in design and execution; Magnezone traps Steel-types such as Ferrothorn, Mega Scizor, Klefki, Jirachi, and Skarmory, facilitating a Mega Altaria sweep. With Magnezone being able to trap and remove a large portion of the Steel-types in the ORAS OU tier, and Mega Altaria's access to Earthquake allowing it to cover the few Steel-types such as Heatran that Magnezone cannot deal with, this core deals effectively with almost all the Steel-types that OU has to offer. Choice Specs Magnezone not only traps Steel-types, but it can also be fantastic to pave the way for Mega Altaria by weakening other Pokémon such as Mega Venusaur and Landorus-T with its Choice Specs boosted attacks.

Mega Altaria also has arguably two of the best defensive typings in Dragon and Fairy, and Magnezone has the most combined resistances and immunities of any Pokémon. As such, this core is not only solid offensively, but it also has solid defensive synergy. Magnezone is able to take common Poison, Steel, Ice, and Fairy attacks for Mega Altaria, whilst in return Mega Altaria resists Fighting and Fire.

  • Manectric-Mega
  • Manectite Manectric @ Manectite
  • Ability: Lightning Rod
  • EVs: 4 Def / 252 SpA / 252 Spe
  • Timid Nature
  • - Thunderbolt
  • - Volt Switch
  • - Flamethrower / Overheat
  • - Hidden Power Ice
  • Weavile
  • Life Orb Weavile @ Life Orb
  • Ability: Pressure
  • EVs: 252 Atk / 4 SpD / 252 Spe
  • Jolly Nature
  • - Knock Off
  • - Icicle Crash
  • - Pursuit
  • - Ice Shard

Mega Manectric's blazing Speed combined with pseudo BoltBeam coverage can make it a menace for most offensive teams to switch into. Of the few Mega Manectric switch-ins that are available to offense teams, Latios is the best option, as it is not 2HKOed by Hidden Power Ice and takes very little from any of Mega Manectric's other attacks thanks to its acceptable special bulk. This is where Weavile comes in, as it is able to Pursuit trap and remove Latios and provides fantastic support for Mega Manectric that can be great in facilitating a sweep. Weavile not only Pursuit traps Latios, but it also can be useful to weaken or remove Ground-types such as Hippowdon, Tank Garchomp, and Landorus-T with STAB Icicle Crash to further support Mega Manectric. In return, Mega Manectric can deal with Water- and Steel-types such as Keldeo, Mega Slowbro, Azumarill, Skarmory, and Mega Scizor for Weavile.

The core can struggle to break through Mega Venusaur and appreciates the support of entry hazards to wear it down. Clefable can also be an issue, as it is not 2HKOed by any combination of attacks and is able to beat both Pokémon 1v1. Weavile can always choose to run Poison Jab to lure Clefable, but the utility of Pursuit is usually more important.

  • Diancie-Mega
  • Diancite Diancie @ Diancite
  • Ability: Clear Body
  • EVs: 32 Atk / 224 SpA / 252 Spe
  • Naive Nature
  • - Moonblast
  • - Diamond Storm
  • - Earth Power / Hidden Power Fire
  • - Protect
  • Talonflame
  • Sky Plate Talonflame @ Sky Plate
  • Ability: Gale Wings
  • EVs: 252 Atk / 4 Def / 252 Spe
  • Jolly Nature
  • - Flare Blitz
  • - Brave Bird
  • - Swords Dance
  • - Roost

This time Talonflame appears in an offensive core and is again paired with a Pokémon with access to Magic Bounce, in this case Mega Diancie. Besides the obvious Magic Bounce to keep Stealth Rock away for Talonflame, this core actually comprises of some nice synergy. Mega Diancie struggles heavily with a plethora of bulky Steel-types such as Mega Scizor, Ferrothorn, and Skarmory. Talonflame has no problem with any of these Pokémon, as well as helping out against some other annoying blocks for Mega Diancie such as Mega Venusaur or even Clefable. In return Mega Diancie can weaken Heatran with Diamond Storm or Earth Power, and it can also do a nice job weakening some bulkier walls like Slowbro, Tank Garchomp, and Rotom-W with Moonblast.

This core can struggle to deal with bulky Water-types with access to Calm Mind such as Slowbro or Suicune. Pokémon with EdgeQuake (Ground + Rock) coverage can also be an issue. Both Will-O-Wisp and more offensively inclined versions of Talonflame work effectively with this core. Mega Diancie often appreciates Will-O-Wisp Talonflame variants' ability to lure in and burn bulky Ground-type Pokémon like Hippowdon, which can otherwise be harder to deal with, but offensive Talonflame can often provide more immediate offensive pressure, which can be useful when trying to punch holes for Mega Diancie so that it can sweep in the late-game.


Whilst building is never going to be easy, establishing a core to build around can be a good starting point and will provide a solid foundation for many teams regardless of the archetype. Hopefully reading this article has given some valuable insight into some common cores.

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