Format: Gen 8 Anything Goes
Zacian-Crowned @ Rusted Sword
Ability: Intrepid Sword
EVs: 216 HP / 156 Atk / 136 Spe
- Play Rough
- Fire Fang
- Sleep Talk / Wild Charge
Rest + Sleep Talk is a pretty interesting combination for Zacian-Crowned. Between Rocky Helmet chip damage, hazards as a whole and pivoting aggressively into Yveltal / Necrozma-DM / Eternatus, Zacian tends to get worn down extremely quickly. Rest grants it the longevity factor while retaining the ability to beat its common checks in Necrozma-DM and Ho-Oh.
The moves are pretty simple here. Play Rough is the chosen STAB option than Behemoth Blade because if the latter is opted, Kyogre would straight-up hard wall the set, which I didn't want. Play Rough also sports more PP than Zacian's other premier STAB option, Behemoth Blade (8 as compared to 16), and for a set which is supposed to last in long-term games the latter felt pretty restrictive and counterproductive. Fire Fang was chosen over Close Combat for the reasons which are already stated above; the former sports more PP which helps in longer games.
As you'll usually be pairing this Zacian-C with Groudon, the Sun would be boosting Fire Fang's base power to 130. With the increased power, Zacian-C's most common check, Necrozma-DM, has a nice chance of being 2HKO'd after a layer of Spikes, and without any prior damage, Necrozma-DM is getting 3HKO'd by it, and with Rest + Sleep Talk, it would get worn down eventually, thus making it easier for you to break NDM. Fire Fang also hits Physically defensive Ferrothorn for a clean OHKO in Sun, and a 2HKO without Sun's boost, though Ferrothorn staying in against Zacian-C is pretty rare.
The last move is more of a filler; you can run Wild Charge for Ho-Oh, but usually, Sleep Talk is a better option when you're not running any Pokémon which can provide the Zacian-C with clerical support, such as Calyrex-Shadow, Xerneas and Blissey (or exotic options such as Magearna).
The EVs allow the Zacian-C to survive a +2 Max Lightning from Xerneas, and KO a chipped one (<50% HP), or bring it to Necrozma-DM's Sunsteel Strike range. The Speed EVs aid it to creep Adamant Zacian and the vast majority of other Jolly Zacians creeping for the 395 benchmark, as well as max Speed base 130s such as Eternatus. If you're running the Zacian-C on a bulky balance, where it is your fastest Pokémon, the Speed EVs would surely help against the aforementioned threats, and is pretty important to run too.
Pokémon which can take care of Groudon, Necrozma-DM, Ho-Oh and opposing Zacian-C are appreciated. As you'll be struggling to break past these Pokémon, especially Ho-Oh if not running Wild Charge, Pokémon such as Zygarde-Complete, Giratina-Altered and Groudon make for great partners. Life Orb Zygarde-Complete can also take down all the aforementioned Pokémon with ease, whereas Zacian-C can slowly chip Lunala and take over Ferrothorn for the Zygarde-C. Giratina-A is fun to use, and it can burn Necrozma-DM, making it even easier to chip it slowly.
Groudon is pretty much mandatory with this Zacian-C, as it summons Sun, which helps in hitting Necrozma-DM for more than 45%, and otherwise getting past it would get pretty difficult. Groudon can also straightaway go for the rolls on the aforementioned Pokémon, while Zacian-C cripples opposing Zygarde-C and Lunala, eventually.
Here is a team build around this Zacian-Crowned set. The team was build by baconeatinassassin for his AGPL game vs. lotiasite. He initially used it as a tool against Choice Band Yveltal, which was gaining heat at that time, and it worked well too. As you can see in the replay, lotiasite had to eventually sack the Eternatus because he couldn't risk the Sun-boosted Fire Fang rolls on NDM, as that would've ended the game then and there. Afterwards, Groudon cleaned, and Zacian's initial wallbreaking was very vital for it to win end-game.
This set can catch the opponent off-guard easily, and with the correct plays and predicts, it becomes a demon late-game. Have fun using it!