Moves
Core Enforcer allows Zygarde-C to deal a decent amount of damage to most Pokemon due to its STAB bonus and respectable Base Power and also has the benefit of suppressing opposing abilities. Worry Seed can be used to remove abilities on slower Pokemon and Fairy-types, such as Mega Audino, Mega Gyarados, and Xerneas. In addition, it is able to replace Normalize Mega Gengar's ability even after it uses Entrainment. However, Zygarde-C is very slow and will not check Fairy-types anyway, so it prefers Core Enforcer. Spectral Thief is used to steal boosts from Pokemon that use setup, such as Primal Groudon and Mega Tyranitar. Topsy-Turvy is an alternative to Spectral Thief to check setup sweepers because even though it doesn't deal any damage, it has more PP, which is useful for PP stalling foes, and it allows Zygarde-C to check Normal-type sweepers like Regigigas and Arceus. Haze bypasses Magic Bounce setup, as well as having the most PP out of any setup-removing attack. However, Magic Bounce setup is relatively uncommon, so Spectral Thief or Topsy-Turvy is preferred.Thousand Waves traps foes that Zygarde-C checks, such as Regigigas, Primal Groudon, and Mega Tyranitar, pressures Steel-types such as Registeel as a respectable Base Power move boosted by STAB, and can be used to help gain momentum.
U-turn allows Zygarde-C to gain momentum against faster foes by bringing in either more powerful wallbreakers or an Imposter user, which can be used to scout the foe's set. Defog removes entry hazards for teammates, letting them come in more safely. Spiky Shield can be used to help Zygarde-C activate its Toxic Orb and scout for coverage and Choice-locked moves; additionally, when Spiky Shield is used in tandem with Wish, it grants Zygarde-C a guaranteed form of recovery. Shore Up gives Zygarde-C the longevity it needs in order to consistently check the Pokemon it wishes to. Due to Zygarde-C's large HP stat, Wish can be used over Shore Up to trade access to instant recovery for the ability to heal teammates immensely. Volt Switch can be used exclusively with Thousand Waves in order to prevent Imposter Pokemon from coming in freely on Zygarde-C while still giving Zygarde-C the ability to pivot in some cases. However, using Volt Switch means Zygarde-C cannot pivot on opposing Ground-types such as Primal Groudon, Mega Steelix, and opposing Zygarde-C.
Set Details
A Relaxed nature maximizes Zygarde's physical bulk and, in conjunction with 0 Speed IVs and EVs, minimizes its Speed. This is incredibly important because going last is often beneficial, letting Zygarde-C remove as many abilities as possible with Core Enforcer, steal the stat boosts of slow Pokemon, and grant more momentum to the team with U-turn. A Toxic Orb in conjunction with Poison Heal grants Zygarde reliable passive recovery, healing 12% per turn. In addition, being poisoned allows Zygarde-C to come in on moves that inflict status conditions such as Spore, Poison Fang, Glare, and Will-O-Wisp. It can also come in on Knock Off.
Usage Tips
Play Zygarde-C carefully. While its bulk is great, its weaknesses are common, and it may be left unable to check Pokemon such as Regigigas and Mega Tyranitar later on in the battle. Pokemon that may lure in Zygarde and hit it with coverage include Mega Blaziken, Mega Mewtwo X, and Primal Groudon. If you're running Topsy-Turvy, be wary of Taunt and Magic Bounce users, as both hinder Zygarde-C's ability to effectively operate as a physical wall. Don't use Wish liberally early on in the game, as the recovery on offensive Pokemon can be crucial later on in the game. Rely on Poison Heal for recovery and only use Wish when you are required to. While passing Wishes to defensive Pokemon isn't a bad idea, Zygarde-C enjoys passing Wishes to offensive Pokemon in order to keep them healthy throughout the course of the battle. This also lets you play your offensive Pokemon more aggressively, allowing you to switch them into entry hazards more often. Whenever Zygarde-C is against a Pokemon faster than it that cannot OHKO it, you may pivot to another Pokemon for momentum. If you predict setup, however, you may use Spectral Thief, Topsy-Turvy, or Haze.
Team Options
Imposter can be very useful for scouting surprise coverage that may hit Zygarde-C. Steel-types such as Registeel, Celesteela, and Ferrothorn can be useful for checking -ate Pokemon that may give Zygarde-C trouble while also checking Ice-, Fairy-, and Dragon-type attacks. In return, Zygarde-C can come in on most Fire-type attacks, which Steel-types cannot take. Strong wallbreakers such as Mega Mewtwo X, Mega Gyarados, and Primal Groudon can be used to break the opposing team while being Imposter-proofed by Zygarde-C. Zygarde-C can also use its low Speed to bring the offensive Pokemon of choice in safely as well as provide Wish support. Special walls such as Ho-Oh, RegenVest Mega Gyarados, and Fur Coat Chansey can take on specially biased offensive threats that give Zygarde-C trouble such as Mega Mewtwo Y, Mega Diancie, and Primal Kyogre.