Got my Shadow Priest macro working about where I want it to.

/assist Focus
/castsequence [nochanneling] reset=24 Vampiric Embrace, Vampiric Touch, Mind blast, Shadow Word: Pain, Devouring Plague, Power Word: Shield, Shadow Word: Death, Mind Blast, Mind Flay, Vampiric Touch, Mind Flay, Mind Blast, Shadow Word: Death, Shadow Word: Pain, Mind Flay, Mind Blast, Power Word: Shield, Devouring Plague, Vampiric Touch, Shadow Word: Death, Mind Blast, Mind Flay, Mind Flay, Shadow Word: Pain, Mind Blast, Shadow Word: Death, Vampiric Touch, Mind Flay, Mind Blast, Power Word: Shield, Mind Flay, Shadow Word: Death, Mind Blast,