God of Magic and Master over Death

The Allfather cannot place full trust in the tension filled Avengers team. Instead he sends his oldest son to assist in retrieving the Tesseract and return his two youngest sons back to Asgard. His oldest son who has not set foot on Midgard in over 2000 years. The one that carries a lightning bolt shaped scar on his forehead and holds a certain mastery over death. [also on AO3]