Its working. Unfortunately the animation is bugged, just like Mage Light in the mages guild line. You toggle the spell on and it's suppose to have an orb of light circling you. It only works half the time for me on Xbox and it never worked for me on PC, but it still applies the buff.
This is something they should fix..... I need to know if it's working. When it works the icon of inferno is like white on the corners when it is working. This is something that needs to be fixed for DK Dark Elf destruction staff builds.