#fire arceus

Type: Fire (with Flame Plate) Ability: Multitype (type changes depending on the held Plate, can't lose item in battle) Stats: 120 HP/120 Attack/120 Defense/120 Special Attack/120 Special Defense/120 Speed

Yes, I know it's been all Arceus lately, there's still another week's worth of types left. Bear with me, and next weekend you'll get Skymin, I promise.

Anyway, here we have the Fire-type version of Arceus. Like all Fire-types, weaknesses are a problem, especially with Kyogre running around everywhere (at least it's not as common as that insane 53% or whatever from 4th gen, but 34% is pretty bad for your survival chances). Luckily, Groudon can be easily paired with it to get the sun shining, and it's probably the best specially-boosting Fire-type in the sun (sorry Ho-oh...) It has its problems with all the Fire resistances in the tier as well, but can work around them to an extent, and is most likely in the top half of usable Arceus forms.

Calm Mind

Item: Flame Plate Ability: Multitype Nature: Timid EV's: 80 HP/252 Special Attack/176 Speed

-Calm Mind -Recover -Flamethrower -Spacial Rend

Yes, unlike the Rock-type, this can Recover, as you're using the Sun (and really, if Kyogre comes in this can't hit it hard without sacrificing a ton of coverage.)

It's really your typical Arceus set. Calm Mind, Recover, STAB move, and coverage. Flamethrower has only 5 less power than Judgment but has that 10% chance to burn, and you really don't lose any important KO's by using it. Spacial Rend came from the Arceus event itself, and is superior to Dragon Pulse mostly due to the Critical Hit rate. The power is slightly higher and accuracy slightly lower (95% isn't bad), but it's mostly the critical hit rate that pushes it over the top. It gets the many Dragons in the tier, including Palkia, to go down.

Counters

Kyogre pretty much wrecks it with any Water-type move or Thunder Wave, brings Rain to weaken the Fire-type moves, and is resistant to Fire.

Tyranitar brings in Sand, resists Fire, is neutral to Dragon, and sometimes runs Stone Edge. Even without it Tyranitar usually comes out on top with Crunch.

Ho-oh has a monster Special Defense and Earthquake, and works as long as Arceus isn't using Thunderbolt.

Snorlax can actually take this if it has Earthquake, and with all the Fire-moves from the Special side a Thick Fat Snorlax isn't a half-bad option in the tier. It actually may handle this tier better than the Fighting-filled standard.