I usually don’t like Shadow Priests much, so I had to do quite a lot of testing and research before I got a spec I was proud to include as a WoW Yoda spec. After all, I have to protect my reputation!
I know that the first thing that will come to most people’s minds are some of the talents that grant spells – those of course being Silence, Archangel and Psychic Horror. My reasons for this are due to the fact that generally a 45 second cool down for only a 3-5 second effect on a target isn’t that good, especially since priests don’t get an interrupt, so you may as well just forego it. Archangel, which you would be using for its Dark Purpose, increases damage of your non damage over time abilities, which aren’t generally used except on trash so it’s only real purpose is just a 90 second delay on just a 5% increase to your mana and a little extra damage to maybe 2 Mind Blast castings. As for Psychic Horror, yes 10 seconds without a weapon is very bad for the melee target, and 3 seconds trembling in fear is also bad, however a 2 min cooldown ruins any benefits it may have. I would much rather prefer to save the points for something a little more useful.
So, now that I have that out of the way, here is the reasoning for what I have chosen for Withering Touch! Darkness is a prerequisite to increase the amount of damage your DoT spells will do and to decrease cast time of your Mind Blast, Vampiric Touch, and Mind Flay. With this spec, your main goal is to gather at least one Shadow Orb through Shadow Word: Pain or Mind Flay, then cast your Mind Blast to gain your 10% DoT buff. The best part about that is that you don’t need all 3 Shadow Orbs to gain the full 10% and having more than 1 Orb doesn’t increase the DoT buff increase, so only 1 orb is needed and the rest is just gravy. So you will want to keep as many enemies as possible to have your DoTs on them.
That being said this will require a lot of mana, which I have already thought of. Masochism, Vampiric Touch, Dispersion, Mental Agility, Veiled Shadows and Glyph of Spirit Tap will all assist in either reducing your mana cost or increasing your mana production. There are also plenty of damage increasing talents to help with efficiency, which I won’t name here since there are so many.
As for the rotation, on a single target – Vampiric Touch will be your opener, followed by your Shadow Word: Pain, Devouring Plague, Mind Blast, Shadow Word: Death, followed by Mind Flay, then continue with Mind Flay and Mind Blast until your DoTs run out, in which you will want to recast them. For multi targets it is slightly different – You will want to choose a target to be your “main” target. This will be the one that will have your Vampiric Touch and Mind Blasts will be cast on. All enemies should have Shadow Word: Pain and you hit them with a Mind Sear. And remember to move around whenever you are casting any of your instant spells, this way you have a chance to proc your Shadowy Apparitions.
All in all, this spec will take down your enemy in writhing pain and agony in no time at all!