As the princess of Fantasinia, Yggdra is the main protagonist of Yggdra Union and the central focalpoint of the story. Yggdra barely escapes from Paltina after Gulcasa ruthlessly murders her family, carrying with her the Gran Centurio, an ancient sword of incarnate justice. Yearning to bring her own justice to bear at Gulcasa's throat, but hunted and defenseless, Yggdra flees into the mountains south of Paltina. There she seeks refuge in a theives' hideout. The Valkyrie twins are in hot pursuit, and seek to capture her. Their callous disregard for the theives becomes a blessing for Yggdra, who is saved when the theives drive off the Bronquians in vengence. Their leader, Milanor, extends a helping hand in exchange for her agreement to offer him Castle Paltina once it has been retaken. Thinking only of revenge against Gulcasa, Yggdra takes Milanor up on his offer.
Yggdra and Milanor successfully rondeveu with the besieged Durant, commander of Fantasinia's 3rd Cavalry. Durant offers her the flag of Fantasinia as a symbol of his and the entire Royal Army's allegiance to her. This is the beginning of Yggdra's long road to retake Paltina.
It is a difficult, treacherous road, full of perplexing situations and moments of self-discovery. The problem of the Undines forces Yggdra to learn what it really means to lead, and of the difficult decisions a leader must sometimes make. The problem of Verlaine Hills proves more difficult for Yggdra, something so seemingly treacherous and unforgivable she cannot bear to act by the advice of Milanor. Here, too, is another hard lesson for the would-be queen.
As grave as the burden of leadership is for Yggdra, it fails to distract her from her most sought after goal: bringing justice to Gulcasa. The sight of Gulcasa at Paltina drives her into a rage, bringing out the worst in her character as she relentlessly pursues the wounded warlord, heedless to her duties to Fantasinia. Her reckless pursuit leads her into a trap set by Gulcasa, who has planned to use her as a sacrifice to Brongaa. In the dark times that follow, Yggdra has ample time to reconsider the rashness of her activity.
Through her ordeal and eventual rescue by Milanor, Yggdra learns the importance of responsibility to one's peers and the discipline necessary to lead. These qualities prove invaluable to her quest for the crown, which she must take in anticipation of a gathering threat to Fantasinia.
At Welheim Holy Land, Yggdra is forced to face her deepest demons. The vanquished leader of Black/White Rose domain appears to her as an apparition of her soul. Here Yggdra must face first hand the darker side of her nature, the problem of using force to bring peace and the uncomfortable emotions it engenders. The Gran Centurio acts as a conduit to Yggdra's inner self, allowing her to distinguish negative from positive emotion and to ward off the negative energies impressed against her by the apparition. Yggdra forgives herself for killing the Rose House leader as a necessary evil required to prevent their negative emotions from creating a catastrophe. This determination allows her to repress her own negative emotion and assauge her self doubt, giving her the strength to lead.
Yggdra advances to the altar of coronation and is crowned "La Pucelle" (French for "divine maiden") by Pope Joachim. Her strength is put to the test by Luciana, who has arrives too late to stop her coronation. Yggdra easily defeats Luciana by the power of the Gran Centurio, which has been awakened by Yggdra's newfound fortitude. The dying words of Pope Joachim remind Yggdra that with strength comes obligation, and that she must never forsake her duty as Queen to Fantasinia. Taking these words to heart, Yggdra resolves to march on Bronquia.
Yggdra's newfound resolve is instrumental to her success in the Bronquia campaign. Citizen militia raise problematic moral questions for the new ruler, questions that only the might of the Holy Sword could possibly answer. Yggdra confidently, unflichingly advances to Flarewerk, accepting as her duty the atrocities she is forced to commit in the name of a greater justice and peace. The way is hard: difficult choices must be made, and the loss of friends and of missed opportunities must be coped with.
Yggdra triumphs over Gulcasa and wins his respect as the dominant will on the continent. No sooner do the flames of war die down, though, than the Isle of Arcadia rises from the sea. Yggdra advances to Arcadia only to learn that the Gran Centurio on which she has come to rely is an instrument in Nessiah's grand scheme. Yggdra must face the fact that the very source of her strength is but a tool for Nessiah's use. Or is it? Yggdra observes that the Gran Centurio can be used for either good or for evil, and resolves to use it for peace. Nessiah is defeated by the power of peace, his hatred overcome.
Having defeated the true source of the darkness lurking on the continent, Yggdra stands at the gates of Heaven. Before her stands an angel, a representative for the beings who cast Nessiah into her world, and with him the curses of the ages. Her final test remains: will she raise her sword to war one more time in protest against the Gods' indifference; or will she reach out to these plausibly amoral powers in search of a greater peace and stability? Does justice always lie with the Holy Sword; or, is there a time and place for confrontation, whatever the implication to principle? The entire world waits with baited breath for her answer.