Born to a family of peasants in Mirrah, an unprivileged region of Drangleic, Lucatiel and her brother joined the army as a means to provide for their family. The two took up fencing at an early age and Lucatiel's prowess on the battlefield eventually earned her a position of Knightess of the Order. Despite her abilities, Lucatiel readily admits that she was far inferior compared to her brother, Aslatiel.
At some point in the past, Aslatiel disappeared and Lucatiel became afflicted with the Undead Curse. She has traveled to Drangleic in hopes of finding both her brother and a cure for the Curse.
Lucatiel can be encountered in four areas over the course of the game. Speaking to her will gradually reveal more of her backstory and allows her to be summoned as a White Phantom to aid in defeating the area's Boss. These areas are
- No-Man's Wharf, near the bonfire
- The Lost Bastille, in one of the ruined towers
- Black Gulch, inside a hidden cave which can be accessed by dropping down from a cliff above
- Earthen Peak, at the bonfire in Lower Earthen Peak
Provided the player as encountered and spoken to her at all four locations, Lucatiel can be found at the first bonfire in Aldia's Keep. If the player has summoned her for all four boss battles and has managed to keep her alive for three of the four battles, she will thank the player for keeping her sane and offer her armor and weapons as a reward.
If the player has failed to keep her alive for three of the four boss battles, her demeanor is very distressed and she will disappear from the game after all her dialogue has been listened to.
Regardless of either outcome, she will not be encountered again after Aldia's Keep and her final fate is left unknown.