When Mind Sear is used with inner focus, The mana cost is reduced 100% and it gains a 25% crit chance per tick. This part is intentional. Now for the little bug, The first time you use mind sear, it isn't consumed, not sure how many times you can use it, but I've had a free 25% crit mind sear 3 times in a row before. Just cast it as normally and let it channel, near the end (1 second remaining) recast it.
Tl;Dr for those who want this in steps
Step 1: Cast Inner Focus
Step 2: Cast Mind sear, let channel until 1 sec remaining
Step 3: Recast Mind sear
Repeat.
The skills used are (If you really need this %26gt;_%26gt;) Mind sear, Level 75 Trainable shadow ability for priests
Inner Focus : 11 point talent in Discipline. Enjoy!
by Ironstalker