Rayquaza @ Draco Plate
Trait: Air Lock
EVs: 240 HP / 16 Atk / 252 SpD
Careful Nature (+SpD, -SpA)
- Dragon Dance
I have used this set on a recent RMT of mine and it works best with a Cleric to heal off the Sleep. The EVs were designed to be able to survive Specs Modest Max HP Water Spout from Kyogre twice and survive with 1% health bar crits also Scarf Timid Kyogre fails to 3HKO. It one shots Kyogre at +1 and Groudon at +2 (who otherwise can't harm Rayquaza like Kyogre could.) Normally stuff like Ferrothorn, Skarmory and Forretress would wall this thing but thank Arceus (Troll Freak) for V-Create, it obliterates the above 3 like they were nothing. It requires no hazard support.
Draco Plate boosts the power of Outrage and I don't have to take Life Orb damage which would otherwise screw me over because I would die from recoil against and it lets me bluff a different item like Expert Belt or Lum Berry. Now I don't outspeed ScarfOgre at +2 but I don't need to lol, I can survive another Water Spout and go to +3 if I want to. +3 Outrage has a high chance to 2HKO Skarmory and Forretress. The chance is slimmer against Ferrothorn but that is nonsense.
Rest is nice for when I find a spot later in the game where I can set up again. I usually come in on one of these trash walls and Rest, they can't do anything. If necessary you can go to a Cleric and remove the Sleep status and come in good as new and ready to fetch more souls.
Rayquaza is incredibly bulky in the defensive stat even without investment 90 base Defense coming off of a 411 HP stat let's me survive 2-3 ExtremeSpeeds from Silk Scarf Adamant EKiller Arceus (max damage is 51%). Against 4 HP EKiller Arceus +2 Outrage is a guaranteed OHKO (minimum damage is 100% damage on the dot lol). +1 Outrage does a maximum of 88% and a minimum of 74% so a low chance to OHKO after Rocks and insanely high chance to OHKO after Rocks and 1 layer of Spikes (lol minimum is 99%).
There are a couple reasons why to choose a purely offensive DD set over this one or a better Bulky Dragon Dancer like Dragonite because of Multiscale and the speed they bring to the table. Dragonite however does not get access to an insanely powerful Fire move which rips through what would otherwise wall it and max Attack and Speed Rayquaza is obviously more powerful and has a higher chance to sweep through teams. Also this requires setting up to do damage and even after a couple DDs may not have the offensive presence to KO everything in it's path.