Starmie

Even with the nerf to its critical hit rate from 22.46% to 18.65%, Starmie is a prominent threat in Stadium OU thanks to its high Speed stat, which gives it the jump on the likes of Tauros, Zapdos and Gengar, as well as its ability to spread paralysis across the opposing team. Its access to a wide array of coverage moves means it can hit many important foes, such as Exeggutor and Slowbro, for super effective damage. On top of this, it has access to Recover, giving it extreme longevity. It also has better physical bulk than Alakazam and Chansey, which are its main competition for the role of paralysis spreader with recovery. Starmie has more flexibility in Stadium OU than standard OU, as it doesn't have to commit to the lead slot or a non-lead slot before seeing the enemy team thanks to the addition of team preview, allowing it to reactively choose a role as needed. The nerf to Hyper Beam in Stadium also works in Starmie's favor, as Tauros and Snorlax with Hyper Beam are less common than in standard OU; this makes them worse at pressuring Starmie.

However, Starmie is completely unable to meaningfully threaten Chansey outside of paralysis and can't fit all the moves it wants to, as it only has 2 free moveslots after Thunder Wave and Recover. This means it either has to give up crucial coverage for foes such as Exeggutor and Slowbr or be unable to offensively pressure Pokemon that take neutral damage from Blizzard + Thunderbolt, such as Snorlax and Jolteon. Starmie is also ruined by paralysis, as it becomes far less offensively and defensively potent, making its job of spreading paralysis quite difficult to do without incurring paralysis itself. This also makes it extremely dangerous for it to switch into Tauros and Snorlax, as it risks getting paralyzed by Body Slam doing so.