Front bar: Light Attack, Stalking Blastbones, Light Attack, Ricochet Skull, Light Attack, Ricochet Skull, Light Attack, Stalking Blastbones, Light Attack, Mystic Siphon, Light Attack, Ricochet Skull, Light Attack, Stalking Blastbones, Light Attack, Skeletal Arcanist, Weapon Swap
Back Bar: Light Attack, Avid Boneyard, Light Attack, Rearming Trap, Light attack, Unstable Wall Of Elements, Weapon Swap.
NOTE: Always fire your ultimate if ready, at the END of the rotation and swap back to the front to be sure to get the most damage out of it (front bar has higher weapon damage).
Also if you feel like you need more ultimate regeneration you can throw in a “Light Attack, Necrotic Potency” before swapping to your front bar after Unstable wall of Elements but try not to hang on the back bar too long.