Omastar

Due to Omastar's extremely low base 55 Speed stat, one might wonder why it should be considered in Ubers when there are much faster Swift Swim sweepers available. However, Omastar's rain-boosted and Choice Specs-boosted Hydro Pump has more power than any other move available to another Swift Swim sweeper, as it can OHKO Arceus after Stealth Rock. In addition, Omastar's secondary Rock typing and excellent base 125 Defense stat allow it to check Extreme Killer Arceus and Life Orb Ho-Oh, two Pokemon that are extremely difficult to check offensively otherwise, effectively in rain. Although Omastar's low base Speed might be a deterrent at first, Omastar still reaches 418 Speed in the rain, which is enough for it to outrun the likes of Darkrai, Mewtwo, and Shaymin-S and OHKO them before they have a chance to strike. Omastar also gets Shell Smash, an excellent boosting move that it can use to end the game, given that it is able to set up and has hazard support. Unfortunately, Omastar does have its weak points. Unlike Kingdra and Kabutops, Omastar is outsped by almost all of the Choice Scarf users commonly seen in Ubers, making it relatively easy to revenge kill. Omastar also struggles to deal with rain stall teams unless it has significant hazard support, as it does not have a diverse movepool. Lastly, Omastar is almost completely useless if Kyogre's rain is removed by an enemy weather setter. Do not let these drawbacks deter you from discounting the fossil as a threat; Omastar's combination of power and Speed makes it a deadly threat that every team needs to prepare for.