Lyndis, more commonly known as Lyn, is one of the Lorca tribe of Sacae, the sole survivor of a massacre of the tribe by the bandits of Taliver. She is the daughter of Hassar, the Lorca chieftain, and Madelyn, the daughter of Lord Hausen of Caelin, and she was named for her late grandmother, Hausen's wife; both of her parents perished in the Taliver assault. Some months after the demise of her tribe, she was embroiled in an inheritance dispute spearheaded by her granduncle Lundgren after learning of her Caelin heritage, and a year afterward joined Eliwood and Hector in their investigations into the Black Fang and the activities of Nergal.
Lyn is one of the three lord characters of Fire Emblem: The Blazing Blade, along with Eliwood and Hector; unlike her co-stars, she was created specifically for Fire Emblem, as was the territory of Caelin, and as such her ultimate fate is not even hinted at in Fire Emblem: The Binding Blade, the chronological successor game.
Months after the death of her parents and the rest of her tribe, living alone in some corner of Sacae, Lyn found a tactician on the ground. She asked to travel with him so she could seek to avenge her dead parents. In Bulgar, she met Sain and Kent, knights of Caelin who were tasked with finding and informing her of her true heritage: that she is the granddaughter of Hausen, Caelin's marquess. From there, her journey changed to travelling to Caelin to to meet her grandfather. Early on, they stopped at a Sacaen shrine and acquire the Mani Katti, a sacred sword that only Lyn can use.
As her journey progressed, it arose that Lundgren, Hausen's younger brother, sought to end her life to ensure his succession to the rule of Caelin by dispatching mercenaries and bandits after her. All the same, Lyn met many companions that joined her in her journey, including Eliwood, the son of the marquess of Pherae, who assisted her from behind the scenes late in her journey. Ultimately, she reached Castle Caelin and slew Lundgren in battle. She was then taken to meet her grandfather, almost dead from the extensive poisoning by Lundgren, who was relieved to at least meet her before his death; she convinced him that he still has much living to do, and he quickly recovered. Still, due to his illness, Lyn took on many of his duties.
One year later, with Caelin still largely under her care, the army of Laus came to Caelin while fleeing Laus itself and attacked the castle. On Hausen's orders, she fled the castle with Sain, Kent, Florina and Wil, leaving him trapped within under the Laus occupation. She dispatched Florina to quickly fly away to find help while the rest of the group stayed put in the dense, movement-hindering forests; Florina found that Eliwood and Hector's group were approaching, and so the two groups eventually united and worked together to free Caelin, with Lyn meeting Eliwood again. After the suppression of the Bern occupation, they found Hausen in the back rooms of the castle, injured by knife-wound from Ephidel but still alive, and first learned of the involvement of the Black Fang in Laus's insurrection. After ensuring that Caelin and her grandfather would be looked after, Lyn set out to accompany Eliwood and Hector for the remainder of their quest; traveling through Bern and to Valor. Along the way, she frequently provided advice and ideas to Eliwood and Hector, acting as a voice of restraint to Hector's brash ways.
And she is reprised by Lani Minella in the English dub and Makiko Ohmoto in the Japanese dub.