Omastar

Omastar is one of the premier rain sweepers in ADV Ubers, utilizing Swift Swim to outspeed most of the unboosted metagame in rain barring very fast Pokemon such as Ninjask and Deoxys-S, as well as Rayquaza with its unique Air Lock ability. Omastar exerts strong offensive pressure with its high Special Attack stat and punishes switches by laying down Spikes to wear down the opponent's team. Its Rock typing and high Defense also protects it from the premier revenge killer in the metagame, Deoxys-A, instead revenge killing it in rain. Offensive rain teams appreciate Omastar's wallbreaking ability and how it reliably forces progress through setting Spikes and using Thief to steal items, limiting the longevity of opposing teams. Omastar does suffer from having very low special bulk and weaknesses to common offensive types, meaning that many Pokemon it can't OHKO such as Latios, Mewtwo, and Groudon can easily take it out, neutering offensive potential from the teams Omastar finds itself on. It also faces some competition from Qwilfish, another Swift Swim user with access to Spikes and a useful tool in Self-Destruct.