Okay, so we need a god of all the main instruments, then a god of overall metal. Then we need some lesser gods for other things to come in as "minor" characters? Take movies for examples.
Although Jack Black is somewhat overrated, The Pick of Destiny and School of Rock are totally acceptable bases for these gods. From this, Ronnie James Dio is totally the god of rock and metal. He's got that total metal voice that most people can recognize, and the way he looks is totally how metal is, too.
Then for the instruments, we need people who are instantly recognizable and iconic as well as playing their instruments. They don't even need to be particularly good at their instruments, it's more about people being like "OH, that guy is this person."
Vocals: Ozzy, Bruce Dickinson
Guitar: Zakk Wylde, Jimmy Page
Bass: Lemmy, Geddy Lee
Drums: Keith Moon, Rick Allen
And everyone knows synth is for pansies.