Gen 9 NU Dual Dance

Porygon-Z @ Mirror Herb
Ability: Adaptability
Tera Type: Ghost / Fighting
EVs: 252 SpA / 4 SpD / 252 Spe
Modest Nature
IVs: 0 Atk
- Tri Attack / Tera Blast
- Shadow Ball
- Nasty Plot
- Agility
A Dual Dance set Porygon-Z can use on HO teams in Gen 9 NU. I already know there's one on here, but I wanted to post one with Tera and a (funny) different item. With Nasty Plot to boost it's Special Attack and Agility to boost its speed, Porygon-Z can be a scary sweeper. Note that you won't always be able to get off both Nasty Plot and Agility, and sometimes you might be able to only get one off. If there are faster Pokemon left on the opposing team, you would want to use Agility. If there aren't faster Pokemon left, you would want to use Nasty Plot. Tri Attack is used for the Normal STAB since it's consistent and has a chance to either burn, paralyze, or freeze. Shadow Ball is chosen as the coverage move to hit Ghost-types named Brambleghast, Chandelure, Basculegion, as well as being able to hit Bronzong and Cresselia super effectively. Plus, no Pokemon (aside from Hisuian Zorua, but it's not a real NU Pokemon) resists both Tri Attack and Shadow Ball. Tera Ghost is used to boost the power of Shadow Ball and lets Porygon-Z become immune to Normal and Fighting moves, which is useful to be immune to Mach Punch and Extreme Speed, as well as being useful against Choice locked Pokemon so you can be able to get off both Nasty Plot and Agility. Do note that using Tera Ghost will make Tri Attack lose the Adaptability boost, so keep that in mind. Alternatively, you can use Tera Blast instead of Tri Attack with Tera Fighting instead of Tera Ghost. Tera Blast Fighting lets Porygon-Z hit Steel-types such as Copperajah and Orthworm super effectively, as well as being able to hit Dark-types such as Incineroar, Umbreon, and Brute Bonnet super effectively. Plus, you don't lose the Adaptability boost on Tera Blast if you turn into a Fighting-type. Adaptability is used to boost your STAB move (and Shadow Ball if you go the Tera Ghost route). Modest Nature is used to give Porygon-Z as much power as possible.
Now for the item, Mirror Herb. At first I used Spell Tag on Dual Dance PZ, but then I settled for Mirror Herb. Mirror Herb is nice to copy stat boosts to make Porygon-Z a scary threat. If you have an opposing Pokemon against a Shell Smash Pokemon such as Torterra, Drednaw, and Minior, you can switch Porygon-Z on the predicted Shell Smash, allowing you to copy the boosts with Mirror Herb. Mirror Herb is also nice to boost past Cresselia and Sylveon, as you can get a free Calm Mind boost from them. So, yeah, that's the reason for Mirror Herb for this set, as it was able to win me games. Enjoy this set!