Thank you both for your replies..... So many people use Spirit Walk, what's the purpose of that? and under what kind of circumstances?
There are two ways of using spirit walk
1) offensive way: use spirit walk to avoid cc from elites and keep outputting your dps, this happens most with CoB build since you need to stay in place and keep channeling the skill
I personally use Jaunt because the 1 extra sec of invincibility gives so much benefit for your dmg and for dodge freezing balls from elites (if there are 2 rounds of freezing , jaunt is long enough to avoid both), some players like mana regen spirit walk too. It is just playing style dependent both are good. With Grave Injustice, at least in mp10 act 1 and 2 , you can have spirit walk up very often
2) defensive way: use spirit walk to dodge attacks, avoid fatal death, and so on.
Just be sure to watch for wallers, it cann't walk through waller's walls.
And of course, spirit walk is supergood for map walking, lol