It's a lot, lot simpler than Hetairos - more like a 1hr playthrough time, based on a set card deck and with far less flexible/expansive rules. I'll write a rough overview of the mechanics soon :)
The six playable characters are:
Avtandil
The hero of the work, from Arabia. He's generally a wise and effective hero, not always morally perfect but cunning, persuasive, and a powerful fighter. Also apparently sings really well.
Brief synopsis of his role in the book:
He's the commander of the armies of Arabia, and after encountering Tariel (who ends up killing several of his men) on a hunting expedition, goes in search of him and ultimately ends up joining him on his quest to rescue the beautiful princess Nestan-Darejan. This involves him taking a considerable amount of leave from the Arabian army, which King Rostevan refuses to grant (but of course he goes anyway and they make up at the end). After hearing Tariel's story, he goes to discover the whereabouts of Nestan-Darejan, which Tariel had been unable to do; he succeeds, going to the distant Kingdom of the Seas and discovering that she has been taken to the sorcerer-kingdom of Kadjeti. Along the way he disguises himself as a merchant, fights pirates, gets involved int minor romantic subplots, and all the other things one expects of a medieval epic hero.
Tariel
The titular Knight in Panther's Skin, hailing from India. Possibly the greatest fighter ever, but also impulsive, reckless, and somewhat mentally brittle.
Brief synopsis of his role in the book:
Once a powerful prince and commander of the armies of India, his love for Nestan-Darejan, the King of India's daughter, led him to murder the Prince of Khwarezm who she had been engaged to be forcibly married to. The King of India then ordered the execution of Nestan-Darejan's nursemaid for allowing their dalliance to occur, and the nursemade (who could do magic and was part-Kadji) in turn commanded her slaves to kidnap Nestan-Darejan, who after a few adventures and another near forced marriage ends up imprisoned in the evil sorcerer-nation of Kadjeti, home of the Kadjis. Tariel spent a lot of time wandering the world looking for her before meeting Avtandil, who persuades him not to kill himself in despair and ends up helping him complete the quest.
Nuradin Phridon
(Or just Phridon for short). The ruler of the small city-state of Mulghazanzar. Probably the most sensible and least morally dubious of the three main male characters, a good knight in his own right, and frequently a source of aid for the heroes.
Brief synopsis of his role in the book:
Phridon helps the other two heroes on numerous occasions, initially meeting Tariel during the latter's wanderings, and later Avtandil when he goes to discover the location of Nestan-Darejan. Tariel helps him defeat his treacherous cousins for control of the islands near Mulghazanzar (which they'd agreed to jointly own then tried to ambush and murder Phridon on when he went hunting there). When they first meet he gives Tariel a super-fast horse (basically Shadowfax with a different colour scheme), and at the climax/end of the book he provides the small army (of 300 men) that makes the final assault on the Kadjis' fortress.
Tinatin
Avtandil's love interest and the heir to the throne of Arabia. Kind and wise but cunning enough to be an effective ruler.
Brief synopsis of her role in the book:
Tinatin is a clear mirror of Tamar, the ruling Queen of Georgia when the original poem was written. She sends Avtandil out on his quest to discover who the mysterious Knight in Panther's Skin is, and Avtandil's love for her is repeatedly brought back as a motif throughout the story. She's also an advisor to her elderly father, King Rostevan, who decides despite tradition to appoint his daughter as heir after his death rather than trying to find another male relative (as indeed happened with Tamar).
Asmat
Maidservant to Nestan-Darejan. Perhaps the only person who cares about Nestan-Darejan as much as Tariel does; she's resilient, wise, and used to living for many years in the wilderness as they wander in search of her mistress.
Brief synopsis of her role in the book:
When Tariel sets out to find Nestan-Darejan, he does so with 200 men and Asmat. By the time Avtandil finds him, all of the 200 have either died, run away, stayed in places along the road, etc - the last two were killed in a brutal fight with several giants, whose cave-fort Tariel and Asmat then occupy deep in the hills. Somehow Asmat survives all of this and provides a groundedness and mental toughness that Tariel completely lacks. She introduces Avtandil to Tariel, and keeps Tariel alive whilst Avtandil is away searching for Nestan-Darejan. At the end of the book she is made queen of one-seventh of India.
Phatman
The wife of the head of the merchants in Gulansharo, the City of Flowers. She rather likes having dalliances away from her decidedly unsatisfying husband, but is otherwise generally kind-hearted and helpful to the heroes. Whilst not a magic user herself, she has several slave-magicians.
Brief synopsis of her role in the book:
When Avtandil arrives in Gulansharo, Phatman becomes infatuated with him and seeks to become his lover. He decides to play along to see if he can obtain any useful information, but they are disrupted by the Chachnagir, another lover of Phatman's who has become increasingly possessive and abusive and threatens to expose Phatman's infidelities and use his influence at court to ruin her house and family. Avtandil then hunts down and kills the Chachnagir, and Phatman then reveals that Nestan-Darejan stayed with her before the King of the Seas (and ruler of Gulansharo) tried to take her as a bride for his son, at which point she escaped and disappeared. It is her magic slave who then sneaks into the Kadjis' fortress and discovers where Nestan-Darejan is, as well as transmitting some letters between Nestan and Avtandil.