Jynx is in the Neverused (NU) tier of competitive battling, where it stands out as one of the tier's best Pokémon. This is due to its great offensive typing, solid overall coverage, wonderful ability in Dry Skin, and access to Lovely Kiss, which allows for it to cripple a Pokémon that it cannot beat. With STAB Psyshock and Focus Blast to bypass common Ice-type counters like Magmortar, Hariyama, and Piloswine, Jynx is a very difficult Pokémon to wall. Dry Skin allows for it to check a number of Water-types like Samurott, Carracosta, and Floatzel, which gives it a nice defensive niche. Jynx's Speed stat is good enough for it to outspeed a number of key threats like Lilligant, Rotom, and Pinsir. Jynx's best set is a Focus Sash set that allows for Jynx to act as a lead and cripple an opponent with Lovely Kiss while putting solid offensive pressure on the opposing teams. Other sets include a Substitute + Nasty Plot set that allows for it to set up on certain defensive Pokémon at the expense of being restricted to mono-Ice coverage and a Choice Scarf set that gives Jynx revenge killing ability while having a fast Lovely Kiss to work with. While Jynx is extremely threatening and a metagame defining threat, it is not without flaws, as its terrible bulk and defensive typing work heavily against it that give it poor defensive utility. Jynx faces competition as a Psychic-type from Mesprit, which has less weaknesses, better bulk, and a solid support movepool with options in Stealth Rock and Healing Wish, and as an Ice-type from Aurorus, which can hit harder with it being able to run Choice Specs without much problem and having Freeze-Dry to break through Water-types easier. Jynx is also rather susceptible to being revenge killed by priority attackers and faster threats like Kangaskhan and Tauros due to its bad bulk.
Jynx is also viable in the Rarelyused (RU) tier of competitive battling. Jynx is a potent threat due to its high Special Attack stat and access to Lovely Kiss, which allows it to put a foe to sleep and gives it a chance to take advantage. With a nice array of coverage options and a wonderful STAB combination to work with, Jynx can take full advantage of its offensive stats. Dry Skin is a nice ability that allows for it to switch into bulky Water-types without taking damage. Jynx's best set is a Lovely Kiss + 3 Attacks set that uses its STAB combination in Ice Beam and Psyshock alongside Focus Blast to take care of a number of threats. It can also run a Choice Scarf set and a Substitute + Nasty Plot set that both can be decently threatening to opposing teams. Jynx is held back by its terrible bulk and vulnerability to priority attacks, which make it relatively easy to revenge kill. Jynx is also set back by its weakness to Stealth Rock and Knock Off, which can hinder its longevity. Its Speed, while good, leaves it outsped by a number of threats like Delphox and Virizion.
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