Thor: Thunderstrike (Mighty Thor) by Tom Defalco

To save Thor's life, Odin places his son into the body of human architect and single father Eric Masterson. And after living for months as Thor, facing such evils as the triple threats of Loki, Ulik and the Enchantress, will Masterson be willing to give up his life as a hero once the real Thor returns? It's Thunder God versus Thunder God, leading to the creation of the new Thunderstrike!