The moveset is Explosion|Shadow Ball|Fire Blast/Flamethrower|Grass Knot/Protect.
Fire Blast vs Flamethrower is your bread and butter Power vs Accuracy argument.
Grass Knot was decided to be the move to be replaced by Protect if neccesary, because there are probably only two Rock types that you will see in the VGC commonly, Tyranitar and Terakion. As for the item, I had the idea of Life Orb or Colbur Berry, though you NEED to use Naive when using Colbur Berry, as this can allow Azelf to survive a Max Attack Adamant Crunch from Tyranitar or a switch on a Pursuit from said Tyranitar. Life Orb helps boosting attacks, cause here surviving isn't a priority, but added Colbur just in case that is wanted.