I actually cast in enmity gear as well, in equip slots that don't have fast cast haste anyway. I noticed early on that casting shadows generated a modest amount of enmity. That new odium ring is godsend to tack onto my mermaid's ring for Ni casting, my Mirke Wardecors has emnity/fastcast on it. And I'm very happy that we have Nokizaru Shuriken and it's dirt cheap.