Possible Clues:

• Believers in Balder
• Like Odin
• European - from Aragon or Seville
• Leif's language
• From Scandinavia
• Scandinavian river - what's under bridge crossing it?
• Like Odin or the Valkyries
• Stupid reason to lose one's tongue
• Outstanding feature about the king of Norway?
• Language that gave us 'berserk'