This form is described as a "devolution." It has reclaimed its original power through Primal Reversion.
Primal Groudon resides in the Uber tier of competitive battling, where it is by far the most centralizing and most used Pokémon in the tier. Due to Primal Groudon's Fire/Ground typing and Desolate Land granting it a Water immunity, Primal Groudon can check Geomancy Xerneas and Primal Kyogre, two significant threats that are stopped in their tracks by Primal Groudon. With great defensive utility, Primal Groudon often finds a spot on teams as it compresses numerous roles into one on both the offensive and defensive spectrum. With very high offensive stats and a high Defense stat, Primal Groudon is the best Stealth Rock setter in the tier, which makes it a very good Pokémon for its overall utility. Its best set is a defensive Stealth Rock setter with maximum Special Defense to better check Xerneas while having utility options outside of Stealth Rock in Roar, Thunder Wave, and Dragon Tail. Primal Groudon has monstrous offensive stats, which allows for it to go a more offensive route as a Stealth Rock setter for those looking for greater offensive power. With Rock Polish and Swords Dance to give it sweeping capability, Primal Groudon can become a sweeper and wallbreaker capable of wrecking a large portion of the tier. A Rock Polish set showcases Primal Groudon's immense sweeping capabilities with a strong STAB in Precipice Blades and the potential to employ a double dance strategy with Swords Dance. It can run a Stealth Rock + Swords Dance set as well which gives it the ability to support and wallbreak at the same time. One unique way that Primal Groudon can be used is a ParaDancer set with Thunder Wave to spread paralysis and Swords Dance to tear apart teams with its brutal attacks. A mixed Rock Polish delivers surprise factor against common Primal Groudon checks by being able to deliver a powerful sun-boosted STAB Fire Blast to certain physically defensive checks. Lastly, a RestTalk set allows for Primal Groudon to consistently check Xerneas and Primal Kyogre without getting worn down too easily. Primal Groudon is very hard to wall once it gets a boost, as it is immune to Thunder Wave and burns and has tremendous power with coverage to handle the majority of the Ubers metagame. The primary flaws in Primal Groudon are that it is relatively slow without a Rock Polish boost and that it must invest a hefty chunk in Special Defense to actually be capable of checking Xerneas without getting worn down too easily. It is also weak to Ground, a common attacking type, and lacks instant recovery while having the Red Orb restrict its item choice. Those flaws are mitigated by Primal Groudon's significant positive attributes that makes it a very common sight in the Uber tier.
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