Viking Warrior horned helmet custom print head for 4" 6" 7" action figures | eBay
Custom Thunder God Viking Helmet Dark Gray Lot for Minifigures - Etsy
Currently there is no Viking looking heavy armor helmet in the game. I think it would make sense to have the Spangenhelm with the cheek guards as a level 3 armor helmet
SLEIPNIR, Viking - Fantasy Helmet Viking and Norman Helmets Helmets, Armour Helmets, Shields - wulflund.com