[Gen 8] Anything Goes
Zygarde @ Life Orb
Ability: Power Construct
EVs: 24 HP / 252 Atk / 232 Spe
Adamant Nature
- Dragon Dance
- Thousand Arrows
- Outrage / Rest
- Stone Edge / Crunch
Zygarde is, arguably the second top offensive threat in the tier alongside Kyogre (sorry Zacian-C you're way too predictable). It has a multiple of options to choose around and no single Pokemon is able to counter all of its sets at once. Bulky Substitute Dragon Dance with Dragon Tail can win games when the opponent relies on Ferrothorn or Ho-Oh to check Zygarde, or even Toxic Substitute set which can surprise Lunala, Xerneas, etc. and give them a painful death.
However, Zygarde-C can become as threatening as Mega-Rayquaza, mowing teams with Life Orb boosted Dynamax moves rather fast-paced instead of a "slow death". The remove of Arceus formes, such as Arceus-Ground, Fairy and Water is really helpful towards this set. Max Quake's effect of boosting your SpD means that it can easily beat even Xerneas and Kyogre against which it would have a tough time otherwise. LO Zyg-C can always get a Dragon Dance on passive stuff like Ho-Oh, Necrozma-DM, Blissey, etc. and either force the opponent to Dynamax or claim 2-3 kills at a minimum.
Life Orb turns many 2HKOes and 3HKOes into OHKOes and 2HKOes. Maximum Atk invest ensure highest amount of damage dealt, while the 24 HP minimize Life Orb recoil. Dragon Dance not only boosts your average attack, but also increases the quite middling speed tier.
Thousand Arrows is one of the best, if not best Ground-type moves as you can Flying-types. Outrage can KO other Zygarde, while Stone Edge has the merit of OHKOing Fast Yveltal at +1, or any Yveltal set with Dynamax as well as dealing with Ho-Oh. Rest is better with Aromatherapy support and gives you longevity to win in longer games. Crunch is a niche option, but allows you to break maximum Spe support Lunala easily with Dynamax, or maximum defense invested sets if Shadow Shield is down.
Teammates
Xerneas forms both a offensive and defensive core with Zygarde-C, as the latter can deal with Necrozma-DM and Ho-Oh, turning them into set-up fodders for Xerneas to clean. Meanwhile, Aromatherapy support from Xerneas can cure Zygarde's burns or poisons, and is good with Rest. It also improofs Ditto if it is locked into Outrage.
Ferrothorn meanwhile helps to deal with Kyogre, though Zygarde-C can handle it alone well. Spikes are still pretty good, as racking up chip damage softens Xerneas to the point you don't need Dynamax to break it. Yveltal can keep Calyrex-S in check, which is probably the most annoying sweeper for Zygarde-C as it can revenge kill it with Choice Scarf or other sets just force Zygarde easily.