I had to get used to wearing a mask and wearing a prosthetic and performing with those things while singing and expressing myself through stylized movement, while keeping it as human as possible so the audience could be closer to the horror of the Phantom.

In February 2012 Butler's publicist announced that Butler had completed a course of treatment for substance abuse of pain killers at a rehab-centre. Despite the film receiving mixed reviews Butler was praised for his performance. It’s the work and not the adulation that has proved to be the most fulfilling.

In 2007 Butler gained recognition through his portrayal of King Leonidas in the film 300. S. He also appeared as a voice actor in How to Train Your Dragon (2010).