Oh, I just realized that them changing my people to look like them would have definitely been a major and severe cause of friction between the groups, and may have even been what started the war. Their mythology (even back then) centered around the Bleeding Sea and the belief that it was the blood of a God and that they had been born from that blood. Your mutating them would've probably been seen as a twisting and distorting the image of them, and thus their god(s).