How about Trick Room? Rhyperior isn´t really the fastest Pokemon but if you´d be in TR, that would actually be a advantage!^^ Search some good TR user (I usually use Reuniclus for this but that´s your decision), a way to set TR up (Follow Me, Rage Powder or Fake Out will usually do on a partner): I´d suggest Amoonguss since you get almost-priority Spore in TR (if it survives, of course...) or maybe Hitmontop bcause it usually carries Priority Moves only so it´ll usually attack first no matter what!^^
As for movesets:
Reuniclus @Life Orb/White Herb
Trait: Magic Guard
IVs: 0 Spe
Nature: Quiet (+SpA; -Spe)
EVs: 252 SpA, 252 HP, 4 Def/SpD
-Psyshock/Psychic
-Focus Blast/HP Fighting
-Shadow Ball
-Trick Room
Pretty mainstream, I know but it´s very good!^^ Psychic is STAB and if you want 10 points more damage, Psyshock if you want to hit stuff like Jellicent or Blissey. Focus Blast works well against Dark types. Alternatively, you can use HP Fighting but that´d mean a serious strength drop but 100 acc... Choose whatever you prefer!^^ Shadow Ball takes care of Ghosts and other Psychics and TR... Yeah, TR is pretty much the main point of this set because you this lets Reuniclus´ pretty bad speed work for you cuz, yeah, it´ll pretty much always attack first!^^
Oh, and item-wise: Use Life Orb for more power but White Herb if you´re scared of Taunt, Fake Out, Encore etc.
Amoonguss @Focus Sash/White Herb
Trait: Effect Spore
EVs: 252 HP, 128 Def, 128SpD
Nature: Relaxed (+Def;-Spe), Sassy (+SpD;-Spe)
IVs: 0 Spe
-Spore
-Rage Powder
-Sludge Bomb
-Giga Drain
The strategy is simple: 1st turn: Rage Powder to set TR up, 2nd Turn: Spore the most threatening Pokemon 3rd turn: Recover with Giga Drain or Spore the 2nd Pokemon!^^ Sludge Bomb helps against other Plants!^^
Items: Yeah, Focus Sash ensures that Reuniclus doesn´t take hits (except for spread moves, of course...) and White Herb safes you from Taunt, Fake Out, Encore etc.!^^
Hitmontop @Life Orb/Eject Button
EVs: 252 HP, 200 Atk, 56 SpD/Def (if you don´t want Intimidate)
Nature: Adamant (+Atk;-SpA), Brave (+Atk;-Spe)
Trait: Intimidate/Technician
Attacks:
-Fake Out
-Mach Punch
-Wide Guard/Detect
-Sucker punch
This one is more all-round supporter-ish: Use Fake Out on the TR counter/Reuniclus counter and make sure TR is set up!^^ Then, attack away!^^ Wide Guard is for protection against Spread moves like Water Spout, Surf and Blizzard (^^)... Oh, and Sucker Punch is coverage!^^
Items: Since Priority moves don´t do much damage, Life Orb might be a good option. Or if you feel a little gimmicky today, try out Eject Button+Intimidate: The Eject Button lets you recycle the effects of Fake Out and Intimidate due to forced switch-out!^^ Might come in handy when Hitmontop can´t do much or when you feel like wanting to annoy the opponent with Fake Out later!^^
