"As far as religious cults go, I'd say your ruler is not the best one. For one, simply telling others that if you aren't of the same species, means you are BELOW yourself, leaves you open to resentment and hatred from those you discriminate against. You invite strife and warfare with such policies. With Eldar, Demons, and Tyranids, such reasons are understandable. For the rest? It is simple misguided hatred. Such zeal only helps so much before you get a tyrannical society built upon tenets that enslave the body and mind to one man's will."