Celestia's daughter, Liliana, was sent to the Wizard world by Discord prompting war where she grew up as Lily Evans. After Voldemort tries to kill Harry, her spell sends him back to Equestria. More precisely, to Sweet Apple Acres where a certain Element of Honesty finds him and adopts the adorable Alicorn. During the NMM arc, he is revealed to be the mysterious Seventh Element of Harmony.