Vivillon

The combination of its access to Quiver Dance, decent Speed and Special Attack, and good offensive typing makes Vivillon one of the deadliest setup sweepers in NU, capable of threatening offensive and defensive teams alike. Sleep Powder is another factor that contributes to how threatening Vivillon is, allowing it to incapacitate even its hardest checks in Pokemon like Steelix, Silvally-Steel, and Rhydon and proving useful in generating setup opportunities. Furthermore, Compound Eyes increasing the accuracy of Vivillon's moves makes Sleep Powder and Hurricane far more reliable than usual. Vivillon also boasts good coverage in Hurricane + Energy Ball, which is enough to hit the entire tier barring most Steel-types neutrally. However, Vivillon's defensive presence is rather poor due to its typing leaving it 4x weak to Stealth Rock and vulnerable to common attacking typings in Electric, Fire, Flying, and Ice and its low defenses preventing it from taking neutral attacks well even after using Quiver Dance and leaving it susceptible to priority from the likes of Sneasel and Medicham. Vivillon is weak unboosted, meaning that it will need to accrue a number of boosts in order to break through bulkier Pokemon like Assault Vest Slowking as well as balance teams.