Blastoise

Blastoise is the most reliable spinner in the RU tier. With a solid pure Water typing, good defenses, and access to Foresight, Blastoise is bound to successfully use Rapid Spin multiple times during matches. It has favorable matchups against many common entry hazard setters in RU, such as Rhyperior and Bronzong, which not only can grant it opportunities to switch-in, but also allows it to remove the source of the entry hazards while also removing entry hazards themselves. Blastoise's typing is also favorable for taking physical attacks, and it has pretty good physical bulk when fully invested. However, Blastoise's lack of reliable recovery and vulnerability to status ailments constantly threaten to shorten its lifespan. RU also has plenty of bulky Water-types to choose from, such as Slowking, Alomomola, and Seismitoad, so Blastoise has a hard time fitting onto teams that don't specifically need Rapid Spin support. While the threat of Scald burns and a respectable base 85 Special Attack make it tricky for most Pokemon to switch into it, Grass-types such as Venusaur and Virizion have next to no issues switching into Blastoise and threatening its team with their powerful attacks. While Blastoise is almost always used exclusively as a spinner, it does the job well and won't let you down.