with shadow fiend up you only cast mind spike and mb. MS will take every set of orbs. MB being instant it will not get the orbs... Its a DPS loss to wait, or to cancel the aura to get MB the orbs. I've tested both ways and just spamming MS as fast as you can and using MB on CD is higher damage. If you have logs proving that your method works better vs what I am saying, please post them.