What are the best Pokemon to clear OR/AS Elite Four post-game?

Question

CONTEXT: I'm trying to beat the elite four to summon Groudon, deoxys and mesprit since I fainted all of them :/ what's the best non-legendary build do do so? (I'm playing Omega ruby)

Comments

Unless your current team is awful, it's probably faster to just use that instead of trying to raise a new team.