Cyane was the Queen of the Northern Amazon Tribe. She was a very powerful amazon, with strong spiritual powers, capable of defeating strong opponents, such as Xena (who was defeated by the Amazon Queen in a physical battle) or Alti (who was defeated by Cyane in a spiritual battle). She fought in the name of courage, which was her holy word.
Cyane nearly killed Xena, when the warrior princess was nothing but an evil warrior, by almost choking her to death barehanded; however, Borias stopped Cyane from doing so, and made a peace treaty with her and her tribe, so they could fight against the centaurs, which were considered as a common enemy. Cyane saw the good in Borias and warned Xena to let him go, so he could accomplish his desire of changing into a good warlord: "He's trying to change, Xena. Let him. If you two stay together, you're just gonna end up killing him." She also saw the good in Xena and offered her to join her tribe, so she could leave her dark past behind, and start a new life as an amazon. Xena felt tempted, and almost accepted Cyane's offering, but in the end, she changed her mind, and betrayed the Amazon Queen, after the evil shamaness, Alti, offered her a "better deal". Xena provoked Cyane, along with all her most powerful amazons, fight with her and impaled them all to wooden pikes, almost vanishing the entire Northern Amazon tribe. She did it in order to help Alti, who needed Cyane's blood to increase her dark powers. After Alti finally managed to drink the Amazon Queen's blood, she kept her soul and the souls of all the Northern amazons trapped in the Amazon Land of the Dead. Alti then used all of their power for herself, and transformed their Amazon essence into evil energy.
Cyane remained trapped in the Amazon Land of the Dead, until the reformed Xena appeared almost 10 years later helping the dead Amazon Queen and her tribe to cross to the other side. Xena trained the new Amazons of the Northern tribe, teaching them what Cyane had taught her, and with their help, managed to kill Alti, finally breaking the evil shamaness' curse. This event gave the deceased amazons a new holy word, so they could finally pass through the gates of eternity. The new word was Love.
Cyane was never seen using any weapons during her appearances in Adventures in the Sin Trade/Adventures in the Sin Trade II; however, she always carried on her back what seemed to be a ritual sword, which appeared to be a soulbound weapon, for it remained attached to her, even in the Amazon Land of the Dead.
From this information, one can infer that she was a skilled swordswoman, and that her sword served her as well as a symbol of her royal powers.