Gothitelle

Gothitelle is the most vile answer to support Arceus formes and Defoggers in the tier. The centralization of the metagame around a great number of threats such as Primal Groudon, Mega Salamence, Ho-Oh, and Xerneas has made role compression unavoidable, resulting in teams that rely on Pokemon such as Klefki, support Arceus formes, Latias, and Latios to glue builds together. Gothitelle is capable of trapping all of these Pokemon with Calm Mind alongside its expansive support movepool that allows it to specify its trapping pool or broaden its utility with moves such as Thunder Wave, Tickle, and Heal Bell. In fact, it's not much of a stretch to say that it turns what would otherwise be a valuable asset to your opponent's team into a liability.

However, the physically offensive metagame especially prevents Gothitelle from excelling in the Uber tier, while its already existent flaws such as average stats, aversion to Dark-types, and little utility against offensive teams are more noticeable than ever. In comparison to other Shadow Tag users, it can be somewhat difficult to justify using, as Wobbuffet has superior bulk and more general utility with Encore, while Mega Gengar possesses an array of options that make it consistent across all matchups with Speed and power to boot. However, Gothitelle's unique trapping pool consisting of dominant threats such as Klefki and support Arceus formes and its ability to eliminate these threats with minimal risk while not taking up a Mega slot give this evil mistress the title of the best breaker of balance and stall in the metagame.