Farangis is a central character in The Heroic Legend of Arslan, serving as a priestess of the Temple of Mithra. Her mission is deeply intertwined with the destiny of the crown prince, Arslan. Upon his birth, a prophecy dictated that a priestess of Mithra would be ordained as the prince's guardian, a calling that Farangis was chosen to fulfill. She was formally dismissed from her temple, suspecting the other priestesses' jealousy of her beauty played a part, but her own disdain for the practices of the invading Lusitanian army also strengthened her resolve to take up her duty.

In terms of personality, Farangis is characterized by her cool-headed, candid, and graceful demeanor. She is a perceptive woman who favors rationality and fairness, seeking to restore harmony to both the people and the spiritual world. While she is formal and respectful towards her allies, she maintains a particularly cold and indifferent attitude towards the musician Gieve, who constantly attempts to serenade and woo her. Despite her composed exterior, she is ruthless towards the Lusitanian enemies, killing any who stand in Arslan's way without hesitation. She views battle as a necessary evil required to defend her values and end the war. She holds her liquor well and takes no pride in her acknowledged beauty, bearing the unwanted advances of men like Gieve and Kubard with a swift and firm rejection. A notable and rare exception to her guarded heart was a man named Eagleelus, who died before the main story begins, and her affections are said to still remain with him.

Farangis's primary motivation is the sacred vow to protect Arslan, which was the dying wish of the High Priestess of her temple. While initially driven by this duty, her loyalty towards the young prince becomes genuine as she grows accustomed to his fair and just judgments. She first appears in the story following the fall of the Parsian capital, Ecbatana. While on her quest to find the prince, she encounters a Lusitanian patrol, whom she engages in combat. Her fight is inadvertently aided by Gieve, who decides to accompany her in the hopes of winning her affection. Together, they locate Arslan and his party. She formally introduces herself and offers an elegy for the dead at Arslan's request, surprising Gieve with her willingness to sing for the souls of fallen enemies. Her skills are a vital asset to the group, often serving as the party's archer and providing a connection to the spiritual forces of their world. At one point, she demonstrates her versatility by using her talents as a dancer to create a diversion and escape from Lusitanian captors.

Her key relationships within Arslan's camp are distinct. She greatly respects the warrior Daryun, and she feels comfortable enough to tease him for showing mercy to an enemy, an act that provokes a jealous reaction from Gieve who suspects she might like the knight. With Arslan, she is respectful and protective, sworn to his service. Her relationship with Gieve is primarily a source of comic relief, as his flirtations and poetry are met with her constant, cold indifference. She feels more at ease with the female member of their group, Alfreed, who confides in her about her own relationship with Narsus and envies Farangis's figure.

Regarding her abilities, Farangis is a formidable combatant, particularly noted for her exceptional skill with a bow. She is capable of making accurate shots from horseback and dispatching multiple soldiers with ease. As a priestess of Mithra, she also has a unique connection to the spirit world. She possesses a whistle used to communicate with djinn and is capable of summoning spirits and firing energy arrows charged with mystical elements like wind, fire, and water. Her development in the narrative is subtle; while her backstory remains less explored compared to some other characters, she evolves from a warrior bound by prophecy to a genuinely loyal and integral member of Arslan's inner circle.