Special Note: Arceus has only been released at level 100, meaning the the only legally obtainable Arceus has a limit of 100 EVs in each stat. The beast isn't available in Shoddy Battle 1, but is correctly programmed into the Pokémon Online battle simulator. Because of extensive playtesting on Pokémon Online, we have a general knowledge on what all the different types are capable of.
Sporting a base 120 in every single stat, plus a ton of moves to choose from, Arceus can do basically anything. Arceus has another quality that sends it way over the top: Multitype. With this ability, Arceus can become any type in the game as long as it holds the right Plate. Essentially, this enables Arceus to be 17 Pokémon in one! There are generally 3 different kinds of Arceus that you should prepare for, but keep in mind that there are many Arceus sets that don't fall into any of the 3 categories.
Swords Dance is Arceus's quickest way to attempt a sweep because it exploits the Uber metagame's vulnerability to physical attacks. With the exception of Normal Arceus, most Swords Dance Arceus will only need two attacks to cover most threats in the Ubers metagame. This allows Arceus to use one of its many filler moves, which can be deadly if you aren't expecting them. ExtremeSpeed is one of the best choices, as it allows Arceus to pick off weakened Pokémon that attempt to stop your sweep. Substitute is a great defense against Will-O-Wisp users that lack Roar, allowing you to turn the tables on your opponent and set up on their check. Finally, Recover is a great option to let Arceus stick around longer. If your Arceus can hit everything in the Ubers metagame with one move, you can run Cosmic Power and Recover simultaneously alongside Swords Dance to truly be a pest.
Calm Mind Arceus work toward a slower sweep than Swords Dance Arceus, but don't let this discourage you from using them. When used in conjunction with Recover, Calm Mind Arceus can easily achieve multiple boosts and become a fast, bulky, and fearsome sweeper that is almost impenetrable on the special side. Thanks to Judgment, Arceus's signature move, many more types have viable Calm Mind sets than they do Swords Dance sets. For Calm Mind sets that only need one attack, there are 3 moves that protect Arceus from status. Substitute is usually the best, as Arceus has enough HP to make 101+ HP Substitutes and Substitute keeps it from being revenge killed. If you are worried about Toxic Spikes or paralysis from Thunder, Refresh is a fine alternative. Finally, if supporting the rest of the team is your preference, Safeguard is always an option.
Arceus isn't limited to being offensive. With its excellent defensive stats and amazing support movepool, Arceus is fully capable of supporting its team. Recover and Stealth Rock, both rare commodities in Uber Pokemon movepools, are staples for support Arceus. Arceus can also use Roar to rack up entry hazard damage and prevent opposing setup. Arceus can also inflict status with Thunder Wave, Toxic, and the elusive Will-O-Wisp. Arceus has plenty of other support moves to choose from too, such as Reflect, Light Screen, Psych Up, Magic Coat, and even Gravity. As for attacking options, Arceus should usually have a STAB attack and/or an attack to check specific threats your team has trouble with, such as Ice Beam for Rayquaza and Garchomp.
Bug Arceus may have an unfortunate weakness to Stealth Rock, but its superb STAB in the Uber tier more than makes up for it. The biggest selling point to Bug Arceus is that it has the only mono-attacking Calm Mind set that beats both Latias and Scizor simultaneously, in addition to sometimes beating Tyranitar. Bug Arceus is also capable of going physical with Swords Dance, X-Scissor, and either a coverage move or Cosmic Power. When using a Bug Arceus with only one attack, though, let it be known that it will be extremely weak to Ho-Oh and Heatran.
Don't be fooled by its inferior Speed, Dark Arceus is by no means a bad Darkrai. Like Bug Arceus, Dark Arceus is a superb Calm Mind user because of its ability to defeat Latias one on one. Unlike Bug Arceus, however, Dark Arceus will have trouble with Scizor and Tyranitar. To make up for this, Dark Arceus lacks a Stealth Rock weakness and smashes through Ghost Arceus, Giratina, and Lugia with Judgment, all of which would easily phaze Bug Arceus away.
Unfortunately, the EV limitations greatly reduce Dragon Arceus's potential, as it cannot outspeed Garchomp, Latias, and Latios. Despite these setbacks, Dragon Arceus still makes a superb mono-attacker, with only Steel-types resisting Judgment. Dragon Arceus can also use Swords Dance, but it must run Recover in order to not be outclassed by Garchomp and Rayquaza.
Under the rain, Electric Arceus becomes one of the most destructive Calm Mind users in the game with STAB Thunder. After one Calm Mind, 252 HP Kyogre is OHKOed and Palkia is OHKOed after Stealth Rock and Spikes damage. Helping Arceus even more is Thunder's 30% chance to paralyze, which can screw over Electric Arceus's offensive checks, like Latias. Electric Arceus even has access to Ice Beam and Grass Knot with which to maul Groudon.
Despite Ubers being loaded with Psychic-types, Fighting Arceus is still an excellent user of Calm Mind. After 2 Calm Mind boosts, Fighting Arceus can 2HKO Blissey with Judgment. When Sleep Clause is in effect, Fighting Arceus becomes one of the best Darkrai checks in the game with Judgment. Fighting Arceus can also run a support set to check Darkrai and lure Latias into a Toxic.
At first, Fire may seem like a bad typing for Arceus. It's weak to Stealth Rock and is totally neutered by Kyogre's rain. However, when used in conjunction with Groudon's sunlight, Fire Arceus is fully capable of sweeping with Calm Mind. Sun and Flame Plate boost Arceus's already powerful STAB Judgment to even higher levels, effectively allowing it to smash through most opponents without a 4x resistance. As a bonus, Fire Arceus can also hit pesky Kyogre switch-ins with Thunder.
Flying may not seem like an appealing typing at first, mainly due to its weakness to Stealth Rock and Thunder, but Flying Arceus is the only Arceus that's immune to Spikes, Toxic Spikes, and Earthquake. Flying Arceus's main use is as a mono-attacking Calm Mind user, since the only common Pokémon that resist Flying in Ubers are Dialga, Jirachi, Heatran, Metagross, and Tyranitar.
With its amazing defensive stats and Recover, Ghost Arceus is by far the best spinblocker in the game for both offensive and defensive teams. On the offensive side, Ghost Arceus is a very potent user of Swords Dance, being able to crush through most stall teams once Skarmory and Groudon are weakened. Ghost Arceus is also a great user of Calm Mind, and can use Substitute over Recover to set up on Blissey. On the supporting side, Ghost Arceus is notable for being the only Stealth Rock user that is immune to Rapid Spin.
Grass may not be the best offensive typing out there, but Grass Arceus has several tricks up its sleeve that make it worthwhile. The biggest selling point of Grass Arceus is that it can use Thunder Wave very well. Thanks to its Grass typing, Groudon will never switch in, allowing you to paralyze almost anything that comes in on Grass Arceus. Grass Arceus is also the closest thing to a Palkia counter in the rain. To add to that, Grass Arceus fares well against Kyogre and Groudon too, slamming both with Grass Knot or Judgment. Grass Arceus is also a viable user of Calm Mind, though make sure to use Judgment over Grass Knot so Wobbuffet won't counter you.
Ground may seem like a strange type for Arceus when Groudon and Garchomp exist, but Ground Arceus separates itself from the crowd by being a potent special attacker and having Recover. Ground Arceus also has the huge bonus of being the only Calm Mind user to be immune to Thunder Wave. Ground Arceus is also a very good user of Swords Dance, and unlike Garchomp and Groudon, Ground Arceus can use Recover to potentially set up multiple Swords Dances.
Ice is a very poor defensive typing, resisting only itself, and being weak to Stealth Rock and Scizor's Bullet Punch. On the bright side, though, Ice is a fantastic offensive type, hitting Rayquaza, Groudon, and Garchomp super effectively. Ice Arceus, like Electric Arceus, is a very good user of the BoltBeam type coverage from Judgment and Thunder. Unlike Electric Arceus, though, Ice Arceus is capable of beating Latias one on one with a Calm Mind set.
While it may seem strange to not take advantage of Arceus's wonderful ability, Normal Arceus may be the most notorious user of Swords Dance in the entire game. This is because Arceus is the only Pokémon in the game besides Smeargle with Swords Dance and STAB ExtremeSpeed. While Swords Dance Normal Arceus may be the most prominent Arceus set of all, Normal Arceus is capable of more than just that. Unlike other Arceus types, Normal Arceus has the option of using other items since it doesn't need a plate. Leftovers in particular is a godsend to Normal Calm Mind Arceus, letting it have even more lasting power than the others. Normal Calm Mind Arceus can also opt to use Life Orb for more power. Because of Leftovers, Normal Arceus also makes a particularly good defensive Pokémon, only being weak to Fighting-type attacks.
Poison typing may seem awful at first, but it's actually fairly good for Arceus. Poison Arceus is one of two Calm Mind Arceus that can beat Blissey without the use of Substitute. While Poison doesn't have nearly as many resistances as Steel, Poison Arceus is neutral to Fire and resists Fighting, both of which are major problems for Steel Arceus. Poison Arceus is also the most viable Toxic Spikes absorber in Ubers, a quality which can be very helpful for many offensive teams. This Arceus is also good in a support role, because it can combine the utilities of phazing and laying down Stealth Rock with Toxic Spikes absorption. Finally, Poison Arceus is one of the best users of Cosmic Power due to its Toxic immunity.
Psychic Arceus is the only Arceus that is totally outclassed across the board. Generally, Ghost Arceus is better than Psychic Arceus in almost every way imaginable, and the many Psychic-types of Ubers also offer stiff competition for this Arceus in other regards. As it stands, the only reason to use Psychic Arceus is if your team can't handle both Poison and Fighting Arceus, and even that's a stretch.
Under the sandstorm started by Tyranitar, Rock Arceus becomes an excellent Calm Minder that is almost impenetrable on the special side. For example, under the sandstorm, a Choice Scarf Palkia rarely 2HKOs +0 Rock Arceus with Surf. Rock Arceus is also notable for being one of the few Calm Minders to actually beat Ho-Oh, thanks to its Rock-type Judgment. Rock Arceus is also a usable Swords Dance sweeper with either Rock Slide or Stone Edge.
Steel Arceus is one of the most threatening Arceus types that exist. With its superb defenses and typing, Steel Arceus is by far the best Dragon-type switch-in in the game. The most threatening set Steel Arceus possess is Calm Mind. While Steel has a reputation for being a poor attacking type, Arceus puts it to excellent use here as its sole attack. Thanks to its Toxic immunity, Steel Arceus is also one of two Calm Minders that defeats Blissey without the use of Substitute, freeing up that slot for Roar. For similar reasons, Steel Arceus is also a great user of Swords Dance. Since the only attack Steel Arceus needs is Iron Head, it can opt to use Cosmic Power over another attack, making Steel Arceus insanely hard to take down. Finally, thanks to Steel Arceus's superb typing, it's an excellent supporting Pokémon.
Under rain, Water Arceus is an excellent sweeper. The most prominent of these sweeping sets is Swords Dance. With just one Swords Dance under its belt and the rain, Waterfall will OHKO Mewtwo and have a chance of OHKOing Wobbuffet and Lugia after Stealth Rock damage. Water Arceus is also a superb Calm Mind user. With just Surf, it can easily run a mono-attacking Calm Mind set that is similar to RestTalk Kyogre, except with immediate recovery and more Speed.
Arceus is an extremely dangerous and versatile Pokémon, but each one of its sets is able to be beaten. This section will list the most prominent counters for the Calm Mind and Swords Dance sets of every type. If one of these two moves isn't viable on a certain type, it won't be included. This will not be an exhaustive list, and will only include Pokémon that have uses outside of countering a certain Arceus set. If a Pokémon is marked with a *, it cannot switch into Arceus, and is only a check. If it is marked with **, it means the Pokémon can only effectively counter a mono-attacker of that type. This only applies if a mono attacker is useful for a given type. Also, take note that Arceus will not be listed as a counter to itself, as it is obvious which types counter each other.