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Jynx has a pretty decent niche. Scarf especially. Hitting 475 Speed (max speed Timid) enabling it to pick off certain Pokemon and out right killing some others. As well as a nice sleep move in Lovely Kiss.
Here's some quick calcs
252 SpA Jynx Psychic vs. 0 HP / 0 SpD Keldeo: 296-350 (91.6 -...