A Rhyperior planned for the future:
Ability: Solid Rock Attacks: Earthquake, Stone Edge, Poison Jab, Avalanche
Which nature, set of EVs and item would you recommend?
Rypherior Adamant Nature +Attack / -Sp. Attack Careful Nature +Sp. def / - Sp. Attack
Item posibilities: Leftlovers - Because rypherior has lots of hp Focus Sash - To Prevent OHKO from Special Sweepers Expert Belt - Due to his good coverage moveset
Also, you should replace poison jab for Megahorn, it will give you more type coverage.