Stormfiends are Rat Ogors creations created by the Clan Skyre. Designed to be front-line shock troops they have the brute force strength of the Rat Ogors with one or two Skyre weapons graphed on to them to give the Stormfiends a shooting attack or better close combat abilities.
General Stormfiends Tactics
Stormfiends are great all-round tactical unit. Armed with the right tools the storm fiends are more than a match for most other units.
Are Stormfiends Clan Skyre or Clan Moulder?
If you are looking for the Skaven Stormfiends rules on the AoS app or in the Chaos army book, then you will find them in the Skaven Skyre section.
Unusually Skaven Stormfiends have both Skyre and Moulder keywords. This means that they fit it very well to either army. It also means that Clan Moulder Herders are great at herding your Skyre Stormfiends if you are fielding a mixed army