RP Flow
RP1 --> RP2 --> Guardians --> RP3 --> RP4 --> RP5 (Optional) --> Boss

RP1: Nest Choice
Minior / Sigilyph / Noivern

Boss Arena Buff for *NOT* taking the following;
Minior:
- Deoxys' Forme Change causes Deoxys to regenerate 5 HP.
Sigilyph:
- Deoxys's Stat Boosting moves adjust the natural stage.
Noivern:
- At the start of each round, Deoxys's team is surrounded by a Razor Wind effect, which breaks after one hit deflected by the barrier. At the end of each round, if the barrier is still up, team is hit by a Razor Wind from X SpA.

RP2: Non-Combat
Put 3 things here. And then some BS arena effects because fuck you.

Guardians:
Aurumoth and Claydol

RP3: Trap Choice
Malamar / Pangoro / Muk-A

Boss Arena Buff for *NOT* taking the following;
Malamar:
- Deoxys's Stat Downs become Stat Ups
Pangoro:
- STAB Attacks always hit mons attempting to use Bounce, Dig, Dive, Dodge, Double Team, Phantom Force, Fly, Take Cover, Teleport, Double Team, Minimize, and always hit before the evasive stage.
Muk-A:
- Upon a Deoxys-Allied Pokémon being KOed, Deoxys gains the abilities of that Pokémon until the end of the match.

RP4: Non-Combat (Ish)
Solrock & Lunatone theming? More arena effects needed.

RP5: Other M
My work here is done!

Boss:
Deoxys, Reuniclus (Splitting - KOing Reuni gets 2x Horde Duosion, KOing a Duosion gets 2x Horde Solosis with halved HP. :3), Horde Ditto Spawns (End of R1/R5/R9/R13, etc.)