Depending on time, I'll either use:
Shadow Bolt, Siphon Life, Curse of Agony, Corruption, Life Tap, Drain Life
or
Immolate, Siphon Life, Curse of Agony, Corruption, Life Tap, Drain Life
or
Siphon Life, Curse of Agony, Corruption, Fear, Life Tap, Drain Life
But... now that I have UA, I'll start with that and add any of the above, with or without fearing the mob. I've considered using Curse of Exaustion after using UA and then fearing the mob when he gets close so as not to need to life tap and drain life and using this tactic on several mobs. What do you think?