I started out making Hades Helmet to be this gorgeous metal filigree kind of thing, but that went horribly wrong , but thats when I realized I could make a lava texture. It was forged in the underworld, right?
The printable foam pattern from Etsy:
https://www.etsy.com/listing/1606266914/diy-spartan-300-eva-foam-helmet-template?ref=yr_purchases
EVA foam: 6mm HD, from SKS props
Foam clay from SKS props and Big Tub o foam-o
If you want more info on how I made this, let me know in the comments.