You can side with Kagha, closing off the Grove and screwing/killing the Tieflings while getting Haslin to help you (because he can't go back to his grove).
Really? I thought there were only two endings? Does this reflect in the final cutscene also?
EDIT: wait never mind, this is the "race war" ending I read about and it is allegedly really bugged. You have inspired me to do yet another playthrough to get this ending though so thank you, haha