There is a genre called Metal. Chains, skulls, blood, leather, etc.
"The Metal Age" is a name of my project, called Mortal Kombat: The Metal Age. A collection of stories, characters designs, maps of the realms, etc.
The Metal Age is also the name of the time period within my project. Time period being called like that due its brutality. Skarlet here being a prime example. Multiple corpses forming vessel for a blood spirit that inhabits it. Hence the missing flesh limbs being replaced by pure blood.
I have no metal powers based characters there, either. It is just the theme.
I hope that finally clarifies it to you.