Due to its wide special movepool, Arceus-Fire can lure in and defeat Pokemon that would otherwise easily beat it. For example, Mega Salamence and Zygarde-C fall to Ice Beam, while Arceus-Water does not appreciate switching into Thunder. Arceus-Fire can also beat the majority of Steel-types, as well as the dangerous Mega Lucario, due to its Fire typing. However, this does not make Arceus-Fire a good Pokemon. It is extremely easy to check defensively, as its coverage moves, especially when unboosted, are rather weak. Additionally, Arceus-Fire's need to carry three offensive moves alongside Calm Mind makes it a very ineffective Calm Mind Arceus forme, as it cannot fit either Recover or Refresh. This, combined with its vulnerability to every entry hazard, particularly Stealth Rock and Toxic Spikes, severely reduces its durability. Primal Kyogre's prominence on bulky offense and balance makes Arceus-Fire's life even harder, as it is one of Arceus-Fire's best checks. Common weaknesses to Ground-, Rock-, and Water-type moves make Arceus-Fire one of the worst Arceus formes from a defensive standpoint. It cannot even make use of its resistance to Fairy-type moves, as Arceus-Fire's specially oriented nature makes it a horrible check to Xerneas. These severe issues mean that Arceus-Fire offers nothing over Primal Groudon from a defensive standpoint and nothing at all over other Calm Mind Arceus formes, such as Arceus-Fairy, Arceus-Dark, Arceus-Ice, and Arceus-Rock, which are all more durable and provide teams with superior defensive and offensive utility. Do not use Arceus-Fire on a serious team.
name: Offensive Calm Mind
move 1: Calm Mind
move 2: Fire Blast
move 3: Ice Beam
move 4: Thunder
item: Flame Plate
evs: 252 SpA / 4 SpD / 252 Spe
Calm Mind boosts Arceus-Fire's offensive presence, lets it capitalize on the few switches it forces from passive Steel-types such as Magearna and Ferrothorn, and lets it hit its many switch-ins harder. Fire Blast is Arceus-Fire's most powerful STAB option and has a situationally useful chance to burn. Judgment can be used if superior accuracy and PP are desired, but the drop in power is rather unsavory. Ice Beam OHKOes Mega Salamence and Rayquaza and deals excellent damage to Zygarde-C. It is also Arceus-Fire's best way of wearing down Giratina-O. Thunder hits Arceus-Water, Primal Kyogre, and Ho-Oh for decent damage.
Maximum Special Attack investment maximizes Arceus-Fire's power. Maximum Speed investment alongside a Timid nature lets Arceus-Fire Speed tie with maximum Speed Arceus formes, such as Swords Dance Arceus-Ground and fast variants of Arceus-Water, and Jolly Mega Salamence.
Arceus-Fire should almost always be brought in after a teammate has fainted or through U-turn due to its awful weakness to every entry hazard, poor defensive typing that leaves it vulnerable to common Ground- and Rock-type coverage moves, and lack of recovery. In some situations, Arceus-Fire can be brought in via aggressive double switching into predicted Steel-type switch-ins, but this is extremely reliant on good prediction. If Arceus-Fire gets in safely, it should either hit the predicted switch-in with the appropriate coverage move or boost with Calm Mind so it can dent a member of the opposing team. For a Calm Mind Arceus forme, Arceus-Fire is very ineffective against bulkier teams due to its lack of Recover and Refresh, so feel free to play it aggressively if it is confronted with this matchup.
Giratina-O and bulky Mega Salamence can remove the entry hazards that plague Arceus-Fire with Defog and offer a useful immunity to Ground-type moves. Primal Groudon also makes a fine teammate, as it checks Ho-Oh and Primal Kyogre and can set up Stealth Rock. Offensive Primal Groudon appreciate Arceus-Fire's ability to remove Zygarde-C and Mega Salamence. Bear in mind, however, that this exacerbates the Ground-type weakness that Arceus-Fire brings to teams. Primal Groudon itself threatens Arceus-Fire, so Zygarde-C and Mega Salamence are effective teammates; both of these Pokemon can also deal with Ho-Oh. Celesteela walls Arceus-Ground, which is very common and very problematic for Arceus-Fire, and provides Arceus-Fire's team with a Ground immunity. Geomancy Xerneas is an effective partner, as it can take advantage of Arceus-Fire's ability to remove the Steel-types that check it, such as Mega Metagross, Mega Scizor, Mega Lucario, Bronzong, and Magearna. Ferrothorn also appreciates Arceus-Fire's ability to defeat Mega Lucario; in return, it can check Primal Kyogre and set up Spikes. Unfortunately, Ferrothorn can be detrimental to momentum; it also compounds the weakness to Ho-Oh that Arceus-Fire brings to a team. Yveltal and Tapu Koko are effective U-turn users that provide Arceus-Fire's team with an immunity to Ground-type moves and an offensive check to Primal Kyogre, respectively. However, Yveltal and Arceus-Fire are both weak to Stealth Rock, while Tapu Koko shares a Ground-type weakness with Arceus-Fire. Palkia can be of use to Arceus-Fire, as it checks Primal Kyogre and can tear through bulky teams with Z-Heal Block.
Arceus-Fire can use Firium Z in conjunction with Overheat to gain access to Inferno Overdrive, which can deal a surprising amount of damage to Primal Groudon switch-ins after a Calm Mind boost. However, your Z-Crystal is usually spent far better on other Pokemon, and Overheat is a bad move to have to rely on after Inferno Overdrive has been used due to the Special Attack drop it causes. Earth Power is Arceus-Fire's best option against Primal Groudon and Rock-types but is useless otherwise. Spacial Rend hits Arceus-Dragon, Palkia, and Giratina-O harder than any of Arceus-Fire's other moves, but it cannot OHKO Mega Salamence after Stealth Rock, which makes it very unappealing. Defensive sets, such as Psych Up and Roar, are totally outclassed by specially defensive Primal Groudon.
Checks and Counters
**Rock-types**: Rock-types completely wall Arceus-Fire, having the offensive and defensive type advantage. Arceus-Rock can boost with Calm Mind alongside Arceus-Fire and can stall it and its weak coverage moves out with Recover. Tyranitar does not like being burned by Fire Blast but can easily switch in on any other move, as its Special Defense is boosted by sand, and 2HKO Arceus-Fire at worst with its Rock-type STAB moves.
**Special Walls**: Both Blissey and Chansey totally wall Arceus-Fire and can Toxic stall it. Unaware Clefable can also beat Arceus-Fire if it is carrying Toxic over Heal Bell, as it ignores Calm Mind boosts and does not come close to ever being 2HKOed by Fire Blast.
**Ground-types**: Swords Dance Arceus-Ground can't switch into Fire Blast if Stealth Rock is up. However, should it come in safely, it can easily OHKO Arceus-Fire with Tectonic Rage. Primal Groudon can't safely switch into Calm Mind- and Desolate Land-boosted Fire Blasts but can otherwise either force Arceus-Fire out or simply eliminate it with Precipice Blades. Excadrill outspeeds Arceus-Fire and OHKOes it with Earthquake if sand is up. However, it cannot switch into Arceus-Fire at all.
**Primal Kyogre**: Offensive variants of Primal Kyogre cannot switch into Thunder if Stealth Rock is up. However, in all other situations, Arceus-Fire is soundly beaten by Primal Kyogre and its super effective Primordial Sea-boosted STAB moves; Arceus-Fire's Fire Blast is also rendered useless by Primal Kyogre's Primordial Sea, making mispredictions extremely costly.
**Arceus-Dragon**: Arceus-Dragon cannot take boosted Ice Beams but can otherwise switch in and safely use Defog on Arceus-Fire.
**Palkia**: Palkia walls Arceus-Fire and can either use it as setup bait for Z-Heal Block or simply remove it with Hydro Pump.
**Ho-Oh**: Ho-Oh cannot safely switch into Thunder if Stealth Rock is up. However, a healthy Ho-Oh can easily shrug off Thunder and, depending on its set, force Arceus-Fire out with the threat of Toxic or Earthquake.
**Faster Pokemon**: Mewtwo, Mega Mewtwo Y, and Deoxys-A all outspeed Arceus-Fire. Mewtwo and Mega Mewtwo Y will always 2HKO Arceus-Fire with Psystrike, while Deoxys-A will OHKO Arceus-Fire with Psycho Boost in Psychic Terrain. None of these Pokemon enjoy stomaching a Fire Blast, however.