Filia and Xelloss: lifelong enemies since the beginning... and yet, there seems to be an emotion besides hatred that has sparked between these two. That emotion could very possibly be respect... perhaps a subtle appreciation... or maybe even a strange admiration. But, could it possibly be... love?
Ever since her adventures with Lina and Co. had begun, Filia had made it as clear as crystal that she wanted to have as little to do with Xelloss as possible. However, that was hardly possible, considering the Trickster Priest's annoying, comedic tactics and tag-a-long habits. And so, she was forced to endure traveling with the very being who had killed a great deal of her ancestors, so many years ago.
In order to stay true to her religion/race (but not necessarily to her heart), Filia openly showed an absolute hatred for Xelloss, and lashed out at him with a barrage of jeers, blames, and insults at every opportunity. He returned her vehement behavior, and together the two of them shared a timeless conflict between mazoku and ryuuzoku.
The real battle -- a conflict between fate and reality, a battle between authentic love and synthetic hate -- has begun.