Cornelia is a non-playable Hume monk in Final Fantasy XI. She is famous in the Republic of Bastok for helping people regardless of their race or social standing. She was one of three Mythril Musketeers deployed on the Multinational Expedition to the Northlands ten years before the Crystal War, but she never returned from this journey.
Cornelia's brother, a gifted monk, was killed by a Yagudo when she was a young woman. Hungry for revenge, she searched Bastok for Oggbi, a Galkan master of martial arts, and asked him to train her. Not wanting to be bothered, Oggbi told Cornelia he would teach her if she obtained a pendant from the Wandering Ghost in the Gusgen Mines. She undertook the challenge and Oggbi expected never to see her again.
Cornelia returned in a fury. Wandering Ghost was not a monster, as she'd been led to believe, but a stubborn Galka miner with a spooky Hume-given name. After spending three days underground and giving hundreds of pieces of ore to Wandering Ghost she could buy his pendant and presented it to a surprised Oggbi demanding he keep his promise. Impressed by the strength and resilience she had demonstrated, Oggbi accepted her as his pupil.
Oggbi and Cornelia were hired to retrieve a San d'Orian scroll that had been stolen by the Orcs of Davoi. As they rummaged through the Orcish fortress they began to feel like common burglars. This notion was compounded when they were caught sneaking into a tent by Raogrimm, a Galkan swordsman of the Mythril Musketeers. Cornelia took offense at the accusatory tone with which Raogrimm greeted her master, but paused when she recognized him as the Talekeeper, the Galkas' leader. Intrigued that a Hume would possess such familiarity with his culture, Raogrimm bantered with Cornelia until Oggbi told her to stop.
One day Oggbi was called to Castle Oztroja to hunt down the Yagudo that had killed Cornelia's brother. Cornelia was eager to depart and have her revenge, but Oggbi forbade her to go. He had deduced her brother's identity when he first met her and had always known her true motivation for accepting his teachings. Having considered that, he still felt she was too inexperienced for the mission and that her perception was dangerously clouded. Cornelia rejected this assessment and departed for Mindartia alone.
When Cornelia returned to Bastok she exhibited no satisfaction at having defeated the Yagudo. She apologized to Oggbi and questioned her feelings. Overhearing the exchange, Raogrimm offered Cornelia some advice. He suggested that, while someone with nothing to lose is often seen as powerful, true strength lies in having something to protect. Cornelia wondered if she would ever defend anything precious and decided to join Raogrimm in the Mythril Musketeers.
As a Musketeer Cornelia often fought alongside Raogrimm and Ulrich, a Hume warrior. Though intimate relationships between Galkas and Humes were forbidden, Cornelia and Raogrimm began a secret romance. Ulrich fancied Cornelia as well, and did not fail to notice their courtship. His jealousy grew into volatile hatred.
Bastok's leaders obtained information suggesting that powerful technology existed within Fei'Yin, a ruined Zilart city in the Beaucedine Glacier. They had planned to dispatch their best Mythril Musketeers to secretly investigate the site, but word of their intentions leaked to neighboring nations. To maintain an air of diplomacy, Bastok invited representatives from the Kingdom of San d'Oria and the Federation of Windurst to participate in the excursion.
Cornelia, Ulrich, and Raogrimm were assigned to this Multinational Expedition. San d'Oria contributed Francmage M Mistalle, an Elvaan knight, while Windurstian minister Iru-Kuiru, a Tarutaru white mage, and his mercenary companion Yow Rabntah, a Mithra ranger, joined the party from Mindartia.
Fei'Yin proved inhospitable, its halls filled with strange machines and ghoulish creatures beyond what the expedition could overcome. They failed to achieve their mission and retreated from the ruins. Hoping to salvage their time in the Northlands, they turned west to see what might lie in Xarcabard.
During their time in this snowy wasteland, the Mythril Musketeers were separated from the other expedition members. Ulrich used this opportunity to attempt to murder Raogrimm, whose relationship with Cornelia and sympathy for Beastmen he could no longer tolerate. Cornelia threw herself before Ulrich's sword and died with Raogrimm at her side while Ulrich fled.
Death did not bring peace to Cornelia's spirit. Lingering between Vana'diel and the dreamworld of Dynamis, she witnessed Raogrimm's descent into rage and his rebirth as the Shadow Lord. She watched helplessly as he teleported across continents to execute the surviving members of their expedition and saw him gather Beastmen to wage the Crystal War and die at the hands of the Alliance of Altana. Without corporeal form there was little she could have done.
Cornelia remains adrift thirty years after her death. When Eald'narche orchestrates the revival of the Shadow Lord and unleashes the Crystal Warriors to destroy him, Cornelia manifests her image long enough to give Raogrimm some comfort. Her love is released from decades of mindless rage, but their troubles are not yet ended.
When Raogrimm became the Shadow Lord a piece of his soul broke away and planted itself in Dynamis. By the time he returns to his senses this splinter has become a towering darkness that threatens the dreamworld and everything beyond. This new Shadow Lord, or Dynamis Lord, pulls at Raogrimm's spirit to become whole again. Raogrimm tries calling out to the champions that had defeated his mortal shell, but cannot maintain a connection to them. It falls to Cornelia to organize a defense against this threat.
Cornelia rallies all adventurers bold or foolish enough to wander into Dynamis. She calls upon the spirits of Ulrich, Francmage, Iru-Kuiru, and Rabntah to guide this makeshift army through the dreamworld. Together they overcome the barriers established by the Dynamis Lord and shatter his obsidian form.
Freed from the pull of his dark counterpart, Raogrimm hears the voice of Diabolos, the true lord of Dynamis. The Avatar explains that a divided soul can never leave the dreamworld, and that Raogrimm is trapped in that realm. Diabolos puts him to use by ordering a vigil that will continue until hatred no longer exists.
Raogrimm is surprised when the spirits of the other expedition members commit themselves to sharing this appointment. They all bear some responsibility for the horrors that passed between them, and will atone for their actions together. Cornelia tells Raogrimm he doesn't have to shoulder his burden alone anymore and promises to stay with him until the world itself is ended.