There are so many anime & manga related to slayers.
Did you know that there are the actual anime in Japan called the Slayers? The series was first published as a Fantasy novel by Kamisaka in 1989, then anime was developed to show it on the TV.
However, it was a true dissapointment for the anime & manga fans that the Slayers was cut off due to the special TV program related to the incident on the Ohm cult thing back in 1995. I actually enjoyed that show, so if they play it again the future, that will be one of the interesting shows from the past!