Zacian is a good revenge killer in AG due to its good Speed and Attack stat, which are further boosted by Choice Scarf and its ability Intrepid Sword. Its good bulk allows it to revenge kill Yveltal and deal with Dragon Dance Zygarde-C. Play Rough allows Zacian to OHKO many prominent Pokemon such as Yveltal, Zekrom, and Marshadow, while Close Combat hits Steel-types such as Zacian-C and Ferrothorn. Crunch allows Zacian to dispatch weakened Necrozma-DM while also ensuring that it can revenge kill a healthy Calyrex-S and is not completely walled by Lunala. Wild Charge heavily damages Ho-Oh, which otherwise walls Zacian very well and threatens to burn it with Sacred Fire. Wild Charge also gives Zacian a functional super effective option for Kyogre. Solar Blade takes advantage of Drought and heavily damages Groudon while also OHKOing Quagsire, which otherwise walls Zacian easily. Maximum Speed investment with a Jolly nature and Choice Scarf allows Zacian to outspeed almost the entire metagame, even Pokemon such as Zekrom and Groudon at +2 Speed, making it easy to revenge kill foes.

Zacian best fits as a revenge killer on bulky offense and balance teams. Pokemon such as Zygarde-C, Ferrothorn, and Eternatus provide great support by switching into its counters in Necrozma-DM and Quagsire and forcing them out. Ferrothorn can set Spikes, allowing Zacian to KO chipped foes, while also checking Kyogre and Xerneas. Groudon provides sun for Solar Blade variants of Zacian. In return, Zacian can deal heavy damage to Pokemon such as Xerneas, Zekrom, and Kyogre that threaten these teammates. Necrozma-DM can switch into Zacian-C, which can OHKO Zacian, and chip it down so Zacian can revenge kill it with Close Combat or Crunch. In return, Zacian pressures Yveltal and Zygarde-C, forcing them to switch out. However, it must be wary of Knock Off and Glare while switching in. On balance teams, Gothitelle can trap Necrozma-DM and Quagsire, allowing Zacian to put huge dents in the opponent's team.

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Other Options

Fire Fang can be used with Groudon to 2HKO a chipped Necrozma-DM, but locking into it puts Zacian at a disadvantage against Pokemon such as Zygarde-C, Zekrom, and Eternatus.

Checks and Counters

Necrozma-DM: Necrozma-DM is the most reliable check for Zacian, since it can take whatever Zacian can dish out while being able to recover health. It can also heavily damage Zacian using Sunsteel Strike in return. Rocky Helmet variants can chip Zacian, allowing priority users such as Marshadow to revenge kill it, and make Zacian's moves less spammable.

Quagsire: Quagsire is a good check to Zacian due to its typing and Unaware ignoring Intrepid Sword's boost. Quagsire can also cripple it using Toxic or Scald. However, it must beware Solar Blade variants, since they can easily OHKO it.

Eternatus: Eternatus's great bulk allows it to soft check Zacian by switching into its moves and stalling it out while consistently recovering its health. Eternatus can also threaten Zacian with Sludge Bomb. However, a specially defensive Eternatus needs to be at full health to switch into Play Rough.