Jynx

Oblivious
Grants immunity to infatuation.
Type Tier
Ice / Psychic BL
Statistics
Min- Min Max Max+
HP
65
- 271 334 -
Atk
50
122 136 199 218
Def
35
95 106 169 185
SpA
115
239 266 329 361
SpD
95
203 226 289 317
Spe
95
203 226 289 317
Name Item Nature

Special Sweeper

Leftovers Timid
Moveset EVs
~ Calm Mind
~ Ice Beam
~ Lovely Kiss
~ Substitute
252 SpA / 4 SpD / 252 Spe

This set can cause a lot of teams trouble. By Sleeping or eliminating Snorlax / Blissey and Steel-types (mainly Metagross and Jirachi), Jynx does not have many counters. A Calm Minded Ice Beam behind a Substitute will hurt nearly everything else, and opposing Specials can do nothing but watch as their team is decimated one by one. Physical Pokémon tend to have low Special Defense as well. It takes some support to work efficiently, so saving Jynx until later on in the game can reward you in the end. The main advantage of Substitute here is so you can scout out Pokémon waking up. If you tried dual coverage like Ice Beam + Psychic instead of Ice Beam + Substitute, if they wake up from their Sleep, they can hit you with a hard physical attack on Jynx's horrid Defense, but with a Substitute, they wake up and break the Substitute, you then have next turn to try and put them back to Sleep. It also helps to block status and keeps Dugtrio and Aerodactyl at bay.

Name Item Nature

CM Trapper

Lum Berry / Leftovers Timid
Moveset EVs
~ Mean Look
~ Lovely Kiss
~ Calm Mind
~ Ice Beam
252 SpA / 4 SpD / 252 Spe

This set is for the overwhelming number of people who switch Blissey into a Sleep move thinking "oh hey it has Natural Cure it won't matter!!" Mean Look on the switch, Lovely Kiss and prepare to setup with Calm Mind for the sweep. Lum Berry is for if they wake up and Paralyze you before you off them with Ice Beam. Not like Leftovers will be doing much anyway, besides saving you from Sand Stream.

Name Item Nature

Fake Tears

Lum Berry / Leftovers Timid
Moveset EVs
~ Lovely Kiss
~ Fake Tears
~ Psychic
~ Ice Beam
252 SpA / 4 SpD / 252 Spe

Fake Tears their counter on the switch and Ice Beam / Psychic away. Metagross will be your biggest fear when using this. This set is only useful with a few layers of Spikes on the field so they cannot switch without penalty.

Name Item Nature

Perish Trapper

Leftovers Timid
Moveset EVs
~ Mean Look
~ Perish Song
~ Substitute
~ Lovely Kiss
252 HP / 70 SpD / 184 Spe

Terrorizes teams if played right. Substitute or Mean Look on switches, then Lovely Kiss. Perish Song while they can't even touch you. If they don't switch, you are dead.

Name Item Nature

JAA Jynx

Lum Berry / Brightpowder Timid
Moveset EVs
~ Ice Beam
~ Fake Out
~ Shadow Ball
~ Psychic
236 Def / 20 SpA / 252 Spe

This is designed to be paired with lead Exploder and Smeargle. Smeargle Endures as your partner Explodes. Then you send out Jynx. Smeargle Spores the faster Pokémon as Jynx uses Fake Out on the other. This means that the enemy does nothing that turn, except get put to Sleep and take negligible damage. Next turn, you Endeavor the awake Pokémon and Ice Beam it for the kill, because Endeavor will put their HP to 1. Continue until all conscious Pokémon are dead, and then kill the Sleeping Pokémon.

Shadow Ball is for Shedinja, who would otherwise destroy this. Psychic is for Gengar, as Endeavor doesn't hit Ghosts. Shadow Ball and Psychic can be somewhat combined into Hidden Power Dark, but Hidden Power Dark doesn't OHKO Gengar, which is very important to do, especially if Gengar has 318 speed or more.

The Speed needs to be absolutely maxed for this, because of Rayquaza. Fake Out and Extremespeed have the same priority, so if they bring out Rayquaza after you Explode on turn 1, you need to be able to Fake Out before they can use Extremespeed, or they can kill Smeargle and ruin the whole strategy. Max Speed Jynx ties at worst with Rayquaza. This surprisingly effective EV spread will always survive Choice Band Rayquaza Extremespeed, and Jynx's role is to kill Pokémon at 1 HP, so Special Attack doesn't really matter. However, this might be too much for some people, which is why another EV spread is to run 16 Defense / 240 Special Attack / 252 Speed. The Defense is to survive non-Choice Band Rayquaza Extremespeed as you Ice Beam it into oblivion. This is not recommended, however, as your killing power doesn't change, and you still cannot beat Dusclops.

Other Options

Hidden Power Fire can really hurt Metagross and Jirachi, do a little more to Regice, and also screw up the uncommon Scizor and Registeel switch-ins. Further, Jynx can learn cool support moves like Wish, Reflect and Light Screen, but there is no reason to use Jynx for that as many other Pokémon are more durable and are much more effective using that. There's nothing noteworthy in the rest of Jynx's movepool: it learns some physical moves, but it does not have the Attack stat to use them effectively, plus it would require EVs out of Special Attack.

EVs

Just max out Speed and Special Attack. Unless you have something very specific to EV it to survive, it's going to die to a physical hit, so you want as few things as possible to be faster than it, and you don't want anything to survive your hits.

Opinion

Can really damage a team, but can't switch into anything or take any sort of hit. This is the definition of a glass cannon in OU.

Counters

Metagross and Jirachi resist Ice Beam x2 and Psychic x4, and have high defensive stats to take a few hits. Sleep Talk Metagross will especially kill Jynx, and Jirachi can Calm Mind up with you. Houndoom can abuse Early Bird to make Lovely Kiss hard to use, resists Ice Beam, is immune to Psychic, and has STAB Flamethrower or Pursuit to kill Jynx. Blissey takes very little from anything Jynx can do, but unless something else has already been put to Sleep, it's just going to be set-up bait, as Natural Cure actually just gives Jynx free turns. Snorlax has Thick Fat and often runs a Sleep Talk set to really screw over Jynx. Registeel and Regice take little from Jynx's Ice Beam, but without Psych Up, Seismic Toss, or Earthquake, Regice can't overcome Jynx's Calm Minds.