Ha, I just did that fight too. I used whichever ward it was that blocks projectiles and elemental + Fire on armor (Elemental still only level 1, even though I'm pretty sure I've had it equipped since I got it). That fight was definitely the hardest of that series.
"so is my word...It will not return to me empty, but will accomplish what I desire and achieve the purpose for which I sent it." - Isaiah 55:11