Ninjask

Despite its unique role, Ninjask struggles in RU for reasons both inherent to itself and to the tier as a whole. Ninjask's ability to passively acquire Speed boosts and Baton Pass them, along with any other secondary buffs acquired in the process, though not necessarily a simple task, immediately establishes a niche in the tier. Bug / Flying is a very unappealing typing defensively, possessing a series of weaknesses to common attacking types (as well as a dangerous Stealth Rock weakness), and 61 / 45 / 50 defenses aren't doing much to mitigate this issue. The inherently bulky nature of the metagame means that Speed boosts often aren't enough for a Pokemon to consistently sweep, meaning that Ninjask often has to either prioritize passing Swords Dance boosts (a role it doesn't perform nearly as well as that of a Speed passer) to a partner for it to apply the offensive pressure necessary to wear down the common defensive cores of the tier, or resign itself to use in the mid- to late-game in order to find a window in which its abilities become pertinent for a sweeper to effectively clean up.

Furthermore, the omnipresence of priority users, such as Entei, Kabutops, and Spiritomb, make both passing and receiving boosts a much more difficult task, forcing the Ninjask user to carefully plan their Baton Pass. Even after all that, there are still multi-hit move users and phazers that can almost completely stop any given Ninjask setup, often forcing it to reserve itself until mid-game to have any impact on the match. Ninjask is a very capable supporter of a plethora of potent Pokemon in RU, but in order to excel in this role, it requires significant support, proper prediction and judgment on the part of the user, and just a pinch of patience.