If you stand near (or even in) one of the regeneration chambers, that will be the one Raze goes for when his health gets down; if you temporarily deactivate that one using the nearby lever (or block his path with your creature, summons and/or his summoned walking armours), he should not be able to make it to the other chamber (Rush Attack, a bow or magic should be able to finish him off).
General Raze how defeated? (D2:ED topic, but AFAIK it is the same in DKS/FoV)
