http://ift.tt/2qZvmMH had no idea until I saw that post of the guy blinking off the edge in the Gul'dan fight and someone commented about it.It makes blink go in the direction you are moving instead of in front of you. I.E. you can backpedal one step and hit blink and go back instead of turning around twice to face the boss again.Talk to a mage trainer and they will have it as a dialogue option and it will give it to you as a passive ability. You can unlearn it the same way. Its free both ways.