>>19839271This sentence isn't always correct when applied to tier changes.
Some Pokemon are extremely good or awfully terrible in a meta just because there are or there is a lack of specific Pokemon that offer support or play the role of a common and popular check and counter for said Pokemon.
Look at Quagsire, it is pretty good in OU where it can wall a significant ammount of good Pokemon but is basically nothing in NU where its ability isn't a great deal.
Or take the Kyurem-B example, is a decent Pokemon in OU, but has lot of flaws at the same time, but when it drops in usage to UU for these reasons, where it can find any of these popular Pokemon that threaten it Kyurem-B only sees the green light and starts to rape everything on its sight without having much problems.
Same can be said of Cresselia and Tornadus, Pokemon have niches and are very good in a tier when used on specific teams, however players prefer to have more solid and safe Pokemon instead of those, so they drop in a lower tier where they don't find lot of counter and checks, and where most of the good C&C are obscure Pokemon. In that scenario they broke or overcentralize the meta.
Slurpuff case fits your sentence tho since it still can be fairly handled.
