Possible Clues:

• God of mischief
• Villainous Norse god in the 2012 film "The Avengers"
• 'The Avengers' villain, 2012
• Villain in 2012's 'The Avengers'
• Evil Norse god
• Shape Changer, his mistress a large woman, her children monsters
• Low-key statement on deity
• Deity in the Edda
• Norse shape-shifter
• Evildoing Norse god