Aldred, one of 100 mages in an ancient circle, and the youngest of them all, visits Equestria to steal back something that was taken from his family years ago- meanwhile, Celestia tries to make amends to him for an evil sin she committed towards him, but isn't doing a good job at it- and she may or may not be able to.

{Rated Teen for harsh language at times}

Edit: After receiving a rather unwarranted comment, I think it would be best to point out this is a human in Equestria story. If this is not your cup of tea, I respect that.