I play on Xbox ... sorry, can't help you that way!
Try another strategy for that battle and first set difficulty on "Casual", if you haven't do that already?
I too had problems to defeat Raze. I succeed via using Hide in Shadows skill, walk to the "levers" to stop both chambers (sommoning chamber where all the Walking Armours are coming out & the Healing chamber where Raze going in)
And maybe try the Charm skill or Summon Demon and your Creature?
Or summon Ghost to help you? (the Ghost using Fireballs and Heal you)
Also nice to know : while your're invisible (using Hide in Shadows), you can use the skill Healing without becoming back visible ! Give you more time.
And put a few points in Stun Arrows. Firewall is also great skill.
Best to make a seperate save game just before the battle and same as much as possible.
O, and I read Magic blast is a good boss killer and also Thousand Strikes !
Good luck and to say to you aida : it's totally not necessary to make soo many posts for help .. have a little bit more patient( waiting for help, I know, it can feel like it's "forever" ) and you'll see people wish to help you