As the angel in charge of Deb's disastrous post-death review, Fred (Ben Feldman) was demoted to be her guardian angel after she took up residence in Jane's body. Fred felt an immediate attraction to Deb's best friend Stacy, and the two jumped a lot of hurdles -- including memory loss, jealousy and infidelity -- to try to make their relationship work. Unfortunately, human emotion proved too complicated and heartbreaking for Fred. At the end of Season 3 he ascended back to heaven, where he was relieved of his guardian angel duties.
Sent down as a replacement at the start of Season 4, Luke (Carter MacIntyre) watched over Jane by buying her apartment building -- thus becoming her landlord -- and by becoming an angel investor (hah!) in the firm. His mission was to encourage Deb to become more like Jane, and in doing so let go of her past life. He tried to stop Jane from indulging the Deb parts of her by making sure Grayson didn't figure out Jane's secret. He also courted Kim briefly.