The photos are classified from recent to ancient.
The helmet is a multi influenced concept, it's based on a Dr Fate foam unfold pepakura model.
The face mask is a petsonal design (influenced here and there...).
I've used basically :
- Plaster+ Elmer (wood) glue
- Hot glue gun
- Metal and copper colour spray paint
The weathering and rusting effects were made with acrylic paint (black, red, yellow,blue, green...).
Sorry not to give more details, but there are many more elaborated and documented Instructables here.