I beat him by using [Ghost Shuriken] as my main damage. Let my [shadow guardian] tank, and sneak in with a [ghost strike] or [Mind strike].
Once the shadow is gone, i bail and wait for cooldown. (using [Blink] to escape from danger if needed) Spam Mediate whenever possible. (Kazuro take awhile to run to you if you [blink] out)
If Kazuro is in "sleeping state" Spam basically all of your damage skill and blink out of there. (Shuriken, Ghost strike, mind strike, shadowbolt even)
Tip: [Ghost shuriken] and [Fire Jailor] effect goes hand in hand for prison lock of enemy. Had 130 focus. My INT and AGI was over 200. Mediate at lv 2 is helpful.
I Beat Kazuro in HM by doing that. of course, i won't tell all of my secrets.