Articuno

Articuno possesses the most powerful unboosted special attack in the game in its Blizzard, giving it offensive prowess rivaled only by the less consistent Moltres. This alone grants Articuno a strong niche in the tier, outspeeding and 2HKOing the mighty Exeggutor. This offense is backed by a reasonable 15% critical hit rate, with critical hit Blizzard OHKOing even Tauros. With Agility, Articuno can function as a late-game sweeper that is very difficult to stop when the stage is set. This is because it isn't just a strong offensive threat: it's also quite bulky, winning against Tauros one-on-one, or even Zapdos if at +2 Speed. Because of the increased presence of Rest Exeggutor, there are many opportunities for Articuno to switch in and turn the game on its head with nuclear damage output.

However, Articuno has some deep pitfalls that make it difficult to use in Stadium OU. Team Preview is a massive hit to its viability, removing all surprise factor that helps set up for a sweep in cartridge play. Articuno only has Normal-type coverage and a poor Attack stat to use it with, so Pokemon like Chansey and Starmie, as well as the rarer Lapras and Cloyster, tend to wall it out. Additionally, its valuable Speed, while high relative to OU, means paralysis inducers force it out, which is worsened by Agility not negating the paralysis Speed drop, unlike standard play. It can use Rest to get rid of it, but this isn't ideal. Due to these flaws, Articuno can be seen as very linear, but its immense power is nothing to sneeze at.