This takes the cake though.
Fratello Metallo, an Italian band formed in 1990 is a heavy metal band with a Capuchin Friar at its head.
Yes, to make things weirder, they opened for 2008's Gods of Metal, Italy's largest concert (held annually), above "metal gods" such as Iron Maiden, Apocalyptica, Slayer, The Dillinger Escape Plan, Judas Priest, and Yngwie Malmsteen.
To be honest, I don't like heavy metal for the most part, nor do I wish to praise any of the previously mentioned bands (except Fratello Metallo, of course). Opening for such high name bands, whether I like them or not, is pretty badass.
The reason why I think this takes the cake over Christian Death Metal is because, not only is it fronted by a monk (AWESOME), I like a few of the songs. Ask anyone who knows me about how much I like heavy music and you will understand the feat they accomplished.
The monk dude, Cesare Bonizzi, is really passionate about this stuff. He became a priest, and shortly after tried to exercise his passion for music. After playing a wide range of things, he discovered his love for metal at a Metallica concert. Now he's pwns noobs.
Check out some music @ some fans myspace!