Pokemon Masters - Ultimate Battle Nita (Glaceon, Runerigus, Zapdos)

Team: Glaceon (6EX, 3/5), Runerigus (6EX+, 3/5), Zapdos (6EX, 3/5)
Feels good to crack this one, which I believe to be the hardest piece of content to date. There are 2 absolute requirements you need to include on your team: weather setting and speed debuffing. Glaceon provides both, as well as being a super-effective striker. Runerigus provides speed debuffs, striking, and utility. Zapdos is our defensive support.
Weather: we need to set it 3 times, once at start, once at 80%, and once at 50%. Glaceon has exactly 3 weather sets, making it very good for this stage.
For speed debuffing - this is not so straightforward. While Glaceon's Icy Wind works, it is not enough. The enemy will simply outpace you in speed buffs. This is where Runerigus comes in. Not only do we get additional speed debuffs, we get the No Stat Increases field effect which also prevents the stat reset that Landorus activates when she syncs. This is insanely helpful because without it, all those stat debuffs you accumulated will go away and you have to start again from scratch.
Striking: Glaceon isn't that powerful, but with the help of Runerigus's monster sync, we are eventually able to whittle the enemy down.
Support: Zapdos does a good enough job providing defensive support and can land some flinch turn skips. Meloetta might be good here, as you get a better turn skip mechanism in Sing. However the defensive support from Rosa is not nearly as good as Zapdos.
With above average flinch luck and perfect execution, we are able to take out Nita.