Board Thread:Warhammer 40k General Discussion/@comment-88.114.255.138-20130111160957/@comment-5880884-20130128114135

It is stated somewhere by GW that Khorne is the strongest and slaanesh is the weakest. As for Nurgle and tzeentch, it is not explicitly stated, though nurgle's standing can change. So well, there is no point arguing.