Moves
Swords Dance boosts Ultra Necrozma's damage output to the point where it can easily KO offensive foes and pressure defensive foes.
STAB Photon Geyser has high damage output, and it becomes Light That Burns the Sky with Ultranecrozium Z.
Earthquake provides Ultra Necrozma with a valuable coverage move to hit Steel-types and common threats like Primal Groudon.
Stone Edge rounds out Ultra Necrozma's coverage by hitting certain Flying-types like Yveltal and Lugia, which would prove to be serious problems to this set. Necrozma-DW's tendency to draw in Yveltal prior to Ultra Bursting makes Stone Edge an effective way to punish it.
Rock Blast can be used instead of Stone Edge to better handle Lugia and Charti Berry variants of Yveltal, but its inconsistency can be hazardous.
Outrage serves as another move to punish Dark-types and other bulky foes that hope to take on Ultra Necrozma with their typing. At +2, Outrage is capable of OHKOing conventional checks like Yveltal and Mega Sableye and, with Stealth Rock up, Arceus-Dark and Lugia.
Brick Break can help Ultra Necrozma lure and punish Dark-types like Arceus-Dark and Tyranitar, but its low damage against Yveltal and inability to hit Mega Sableye leaves Outrage as generally a better method to combat them.
Set Details
32 Defense EVs ensure that Ultra Necrozma survives Life Orb Marshadow's Shadow Sneak after Stealth Rock damage. Speed is maximized to outspeed Marshadow and Shaymin-Sky and tie with opposing Ultra Necrozma, while the remainder of the EVs are invested in Attack to maximize Ultra Necrozma's damage output.
Ultranecrozium Z gives Necrozma-DW an access to Ultra Burst, letting it overcome its low Speed and drastically improve its offensive stats when its spinblocking utility is no longer needed. Ultranecrozium Z also allows Ultra Necrozma to use Light That Burns the Sky.
Neuroforce makes super effective moves more powerful, allowing Ultra Necrozma to score OHKOs with boosted Earthquake and Stone Edge on foes like Primal Groudon, Necrozma-DM, and Yveltal.
Usage Tips
Necrozma-DW's disappointing defensive typing heavily limits its opportunity to switch into most attacks. Apart from offensively checking Mewtwo and occasionally switching into predicted Normal- or Fighting-type moves, it is recommended for Necrozma-DW to be switched in to block Rapid Spin from Cloyster or Excadrill or revenge kill a foe.
It is very rare that Necrozma-DW's defensive typing is better than Ultra Necrozma's defensive typing, so Ultra Burst as soon as Necrozma-DW's spinblocking utility is no longer needed so Ultra Necrozma can start pressuring Rapid Spin users or any foe it is contending against. Ultra Bursting also allows Necrozma-DW to overcome its underwhelming Speed and threaten significantly more foes.
Be quick to set up Swords Dance by taking advantage of defensive foes or forced switches. This allows Ultra Necrozma to pressure foes, particularly Defog users, helping Ultra Necrozma keep entry hazards on the field after it has lost its Ghost typing after Ultra Bursting.
Light That Burns the Sky cannot be used until the turn after Necrozma-DW has used Ultra Burst. The Z-Move should also be used with caution, as its availability has crucial influence on Ultra Necrozma's matchup against the likes of support Arceus formes.
While Ultra Necrozma is capable of rampaging through most teams after a Swords Dance, foes like Mega Gengar, Choice Scarf Xerneas, and most Yveltal variants can easily revenge kill Ultra Necrozma, with Yveltal being able to revenge kill Ultra Necrozma with Sucker Punch as well. Ensure these foes are dealt with beforehand; Sticky Web prevents the former two from effectively combating Ultra Necrozma, and Stealth Rock support and offensive pressure will keep Yveltal in line.
Team Options
The best utilities Necrozma-DW can provide to its team are spinblocking and wallbreaking. Therefore, it is best fit on offensive teams, where dedicated hazard setters can set entry hazards to facilitate Necrozma-DW's sweep, while Necrozma-DW can block Rapid Spin and heavily pressure many Defog users. Sticky Web is the best hazard for Necrozma-DW, as it allows Ultra Necrozma to defeat its offensive checks like Mega Gengar and Choice Scarf Xerneas. Smeargle can set Sticky Web while potentially crippling faster threats like Yveltal and Mewtwo with Nuzzle, allowing Necrozma-DW to better deal with them.
Cloyster, Excadrill, and Deoxys-S are also appropriate options for entry hazard setters for offensive teams. Although Necrozma-DW would generally prefer Sticky Web, the former two's Rapid Spin is always useful, and Excadrill's ability to set Stealth Rock and use Toxic on Mega Sableye is appreciated for Necrozma-DW lacking Outrage. Deoxys-S can also, depending on its moveset, set Stealth Rock against Mega Sableye and situationally provide Necrozma-DW with more preferable hazards, as it has access to both Stealth Rock and Spikes.
Offensive teammates with Stealth Rock are needed if a Sticky Web user is employed. Both Primal Groudon and Dialga can dent problematic Steel-types with their Fire-type attacks and set Stealth Rock, which is helpful for Necrozma-DW when against Yveltal and Lugia.
As Necrozma-DW is vulnerable to Dark- and Ghost-types, offensive checks to them are needed. Yveltal can pivot into Dark-type attacks and check Ghost-types. Depending on the variant, Yveltal can prevent Defog with Taunt or safely bring Necrozma-DW into the field with U-turn. Xerneas offensively checks Dark-types, Marshadow, and Giratina-O, and it can take advantage of Ultra Necrozma weakening Steel-types to clean up late-game. Tapu Lele offensively checks Dark-types and summons Psychic Terrain, which protects Necrozma-DW from priority moves and makes Photon Geyser immensely powerful.
Other wallbreakers like Primal Kyogre, Rayquaza, and Marshadow can assist Necrozma-DW's sweep by hindering defensive cores.
