Theory about Ashi [SPOILERS]

They probably fell in love due to their similar origins, as Ashi is Asian. I wonder... were the daughters of Aku, along with the other priestesses, descendants of Jack's hometown gradually building hate for Jack for not being able to protect them as time passes? It's incredible to see how it takes such a long time for a peaceful Asian hierarchy to turn from peaceful to hateful. The High Priestess allowed the other priestesses to die, because she finally had daughters with the blood of Aku, making them powerful and with the greatest hatred possible towards Jack.

As for the bittersweet ending, I wonder of the possibility that Jack will meet the woman from whom the priestesses descended and fall in love with her, as she'd be genetically and spiritually similar to Ashi. And instead of causing hate to build up while descending, love and harmony shall.