Lots of discussion lately about the HoS. The proc is nigh non-existent and without free will, it cannot really compete with Mage Hat or Helm of Khan.
A suggestion: Delete the proc and buff the phasing (and explain what phasing is) or add Free Will. THEN create The Shield of the Shifter (maybe a better name out there). A second thought is to delete the hood in it's entirety and re-purpose the skin later.
*Procs will occur more often because of blocks
*It will encourage wizards and thieves to train level 6 and beyond shield usage
*It will give wizards another CHOICE between 2-handed +100 SDM weapons or shield and short sword
Thank you for your time.