Ok heres a pretty good team for the elite four.

Empolleon make sure he knows Drill peck, Metal claw, bubblebeam, and Hydro pump.
Uxie make sure it knows Yawn, charge beam, future sight, and any other move.
Azelf it can know any move.
Dialga/Palkia make sure it knows Metal Claw, Ancient Power, Dragon Claw, and Roar of time.
Golbat make sure it knows Fly, Payback, U-turn, and any other move.
Machoke make sure it knows flamethrower, submission, cross chop, and anyother move.

This works, I beat the elite for and the champion with these pokemon.

( Note: Make sure you have a couple of ethers you will need it for Empolleon.) Hope i helped!!!:)