I'm deeply sorry this took over a month, some serious real life stuff happened recently, but still, I shouldn't have taken this long. Anyways, I mostly focused on fixing up the prose and organization, and only really added details I thought could help out the analysis (there is one notable omission though, I'm not really sure Landorus-T fits the best as a Steel Arceus pair). Go check this @
Oglemi
<p>This Arceus is a great choice for a supportive Steel Pokémon. While it may lack the Leftovers recovery that other Steel=types such as Ferrothorn, Jirachi, and Skarmory offer, Arceus-Steel's superior stats and versatile movepool set it apart. Especially useful is the fact that Arceus-Steel is the fastest and most specially bulky Steel-type in Ubers!</p>
<p>Arceus-Steel is one of the few Steel Pokémon to learn Will-O-Wisp, so it's a given on a defensive set, allowing Arceus-Steel to cripple most physical attackers. Note that this isn't a sure fire way to cripple Normal Arceus, as Will-O-Wisp missing can lead to Arceus-Steel risking a OHKO from a boosted Earthquake. However, since most Normal Arceus don't run max Speed, Arceus-Steel can act as an emergency check if your team is running out of options to deal with it.</p>
<p>Recover is the other major jewel in Arceus-Steel's crown, meaning it isn't forced to rely on Wish, Rest, or other less reliable methods of healing like most other Steel-types! Arceus-Steel's longevity also makes it a great phazer. Roar is the reliable and immediate option for phazing, while Perish Song is a slower, more risky method that has the advantage of dooming the last Pokémon standing. When it comes to offensive options, Ice Beam is the prime choice. Ice Beam allows Arceus-Steel to slay a wide variety of 4x Ice weak Pokémon such as Rayquaza and Landorus, while also dealing good damage to Groudon, Giratina-O, and Zekrom. Judgment's coverage isn't nearly as good, but it hits Kyurem-W, Terrakion, and Tyranitar. Kyurem-W in particular can actually defeat Arceus-Steel that don't run Judgment!</p>
<p>Timid and max Speed let Arceus-Steel speed tie with other Arceus, but if you want less Speed for more defensive investment, you can run anywhere from Timid and 176 Speed EVs to outspeed Latias and Latios, to a Calm or Bold nature with 168 Speed EVs to outspeed Rayquaza and Kyurem-W.</p>
[ADDITIONAL COMMENTS]
<p>Arceus-Steel has a few other options up its sleeve, but finding moves to replace is tough, as removing Will-O-Wisp and your phazing move lessens Arceus-Steel's utility, while replacing the attacking move makes Arceus-Steel even bigger Taunt bait. Stealth Rock is an option if your team is desperate for fitting in a hazards user. Toxic allows Steel-Arceus to cripple Ho-Oh switch-ins and dangerous Calm Mind users. If your team is extremely weak to Ho-Oh, you also have the more direct option of running Stone Edge. Finally, Magic Coat prevents Ferrothorn from setting up hazards, and can surprise Deoxys-S leads (though note that Fire Punch will 4HKO Arceus-Steel).</p>
<p>Since Arceus-Steel is such a great phazer, it's only natural that Spikes users such as the Deoxys formes, Forretress, Ferrothorn, and Skarmory will make good choices as teammates, despite the typing redundancies. However, in a horribly ironic twist of fate, Arceus-Steel itself is very vulnerable to getting set up on by hazard setters, so Rapid Spinners such as Forretress, Tentacruel, Excadrill, and Kabutops are good teammates, in addition to the riskier option of using a Magic Bounce Pokémon such as Xatu.</p>
<p>Arceus-Steel has serious problems with several common Pokémon on Sun teams, such as Ho-Oh, Kyurem-W (without Judgment), and Reshiram. Other Special Attackers such as Arceus-Ground, Arceus-Fighting, and and Kyogre also make it important to cover Water, Fighting, and Ground-type attacks. All of this makes Kyogre an excellent teammate. Not only does Kyogre nullify Arceus-Steel's Fire and Sun weakness with Drizzle, it also uses Arceus-Fighting and Arceus-Ground as platforms to launch it's torrential assault. In return, Arceus-Steel does a good job of checking Latias for Kyogre. Just be warned, even bulky Kyogre will take a lot from Ho-Oh's Brave Bird! When it comes to typing synergy, floating Dragons such as Giratina-O and Latias also have great typing synergy with Arceus-Steel, being resistant or immune to all of Arceus-Steel's weaknesses, and Arceus-Steel covering theirs.</p>