If you want to use him, you need to be able to land 10 combos every round.
So the reply is easy: Use level 80 talent instead of dance of impetus, so you'll start by removing all the buffs/shields on 3 enemies and you apply also poison.
You won't be able to use both, but you don't need it. The damage you'll land in round 1 will be so high in comparison with what you do now that is the same even if you c*e only one of the two mysteries on round 2.