After his mother died, Magnus was living the life. By that, he was homeless and basically only eating falafel. You, being a son of Odin, took a liking to the young son of Frey. After all, you were homeless before you died...

Magnus was sleeping, not so soundly, under a bridge on a cold rainy night. Stupid Boston... as one of his self appointed guardians, you couldn't let him freeze... like you did.