User blog comment:Supahbadmarine/Canon Policy Discussion 2:Empire and Xenos/@comment-2253300-20131108080503/@comment-2253300-20131108080647

Also I don't think that a modern Xenos race should be able to match or surpass the technology of the Eldar, and certainly not C'tan. I might be able to see certain background races (as in no longer active, existing or possessing said levels of tech) to eexist if treated in a historical context though.