As he collects blood vials and rune pyramids , Kain 's maximum blood and energy capacity rises .
Over the course of the main quest , Kain acquires many items and abilities , which facilitate increasingly nonlinear exploration .
As Kain collects blood vials and rune pyramids , Kain 's maximum blood and energy capacity rises .
Over the course of the main quest , Kain acquires many items and abilities , which facilitate increasingly nonlinear exploration .