Lumineon (F) @ Normalium Z
Ability: Swift Swim
EVs: 4 HP / 252 Atk / 252 Spe
This set is aimed to sweep and is made for the Battle Spot Singles Format. This set requires rain support to function properly, as rain boosts the power of Waterfall and doubles Lumineon's speed, making it hard to revenge kill. Memento support is also needed to allow Lumineon to survive a hit, or force out the current Pokemon on the field so Lumineon can pull off Z-Splash. While not mandatory, Stealth Rock and Spikes support can break focus sashes and help wear down bulkier Pokemon; however, you are only allowed to bring three Pokemon to Battle Spot Singles so it may be hard to fit all the support onto one team: Hazards should never be prioritized over Rain and Memento as the latter two are mandatory to pull off a sweep. One thing to note is that this set loses to priority; While Psychic Terrain may be handy, it's hard to fit onto a team. Splash is used in conjunction with Normalium-Z to grant Lumineon with three attack boosts, making it hit surprisingly hard. Endure allows Lumineon to get down to 1 HP and power up Flail to 200 base power. Waterfall is Lumineons STAB and most reliable physical move outside of Flail. It also gets boosted by the rain. Swift Swim doubles Lumineons speed making it harder to revenge kill. 252 attack EVs, along with an adamant nature allow Lumineon to hit as hard as possible. 252 speed EVs ensure Lumineon is never revenge killed by timid Choice Scarf Naganadel; the fastest common revenge killer in the Battle Spot Singles format. This also means that other common Choice Scarf users, such as Tapu Lele cannot revenge kill Lumineon. The remaining 4 EVs go into HP to give Lumineon an odd numbered HP stat.
Lumineon should come in and try to sweep once Rain is set up and a Pokemon has used Memento before sending Lumineon in, to allow it to set up Z-Splash on a target with minus two in attacking stats or on a switch. It should then use Endure to get down to 1 HP to bring Flail to 200 base power. The combination of a rain-boosted Waterfall and a 200 base power Flail should then be used to break through the opponents team.
As Lumineon needs Rain and Memento support, Pokemon that can set these up are mandatory. Some examples include Whimsicott and Uxie. Whimsicott's Encore is also very nice to stop opponents from setting up too early. It is recommended that either one of the former two hold a Damp Rock to extend the rain. Lumineon may struggle to break through extremely bulky Pokemon (mostly water types, such as Jellicent), so wall breakers pair well and can be used in the final team slot. A good example is Tsareena as Tsareena can easily break through bulky Pokemon, and water types with its powerful moves which include Power Whip, High Jump Kick and Knock Off. Tsareena also comes with some utility as it can block priority with its Queenly Majesty ability, or bring in Lumineon safely with U-turn. As Tsareena is a grass type, fire type Pokemon will want to come in on Tsareena, so once Tsareena U-turns on the predicted switch, Lumineon can come in safely and force the Pokemon with the type disadvantage out and get off a Z-Splash on the predicted switch. Tsareena also appreciates the rain as it weakens fire-type moves.