Kylier

Seventeen years of age and a griffon breeder, Kylier is Milanor's longtime friend and supporter, and an honorary member of his band of thieves. While she's ordinarily a kind and cheerful girl, noticing that Milanor has taken up with Yggdra causes her to be rude, crude, and suspicious. Although Milanor doesn't understand why, it's revealed to the player that Kylier acts like this because she's in love with him. She has jumped to conclusions that Milanor loves Yggdra, making her incredibly jealous. Kylier's reasons for hating Yggdra go deeper than that, though—it turns out that Yggdra's family were responsible for destroying the civilization of the Vanir, Kylier's race, and exiled them to the barren wastes of Lost Aries. While over the course of the game, Kylier grows to like Yggdra as a person, their conflicting ideas on war and Kylier's bitterness towards Yggdra prevents her from permanently joining up with the Royal Army. In the end, Kylier sacrifices herself to allow the Royal Army to move forward in their conquest of Bronquia, which impacts Milanor deeply (and causes him to realize his own feelings for her). Source: yggdra union wiki