“We 'Zoa’s magic warriors' were, for the captive Zoans at least, something like gods... You saved me from the stake, so I entrusted everything to you. For someone like me, who lost her family, you were the only hope remaining. Despite that, to flee and betray the pontifex... I could never have imagined doing something like that.”
—Sierra, in a conversation with Shigen
About five years prior to the game's events, Sierra was saved from her execution at the stake by Shigen. When he asked her to leave the Theocracy of Gerxel with him, she refused and called him a traitor. After Shigen left, she continued thinking about his words and eventually left the Gerxel Church, knowing that Gwenchaos has no intention of helping the Zoans.
If Shigen is defeated at the Sealed Bridge, Sierra will appear and save him, as she feels the need to repay him. After the end of the chapter, she and Shigen join Holmes's army. During a conversation with Shigen, she states that she will always follow him.
Depending on events triggered during the story, Sierra can accompany Shigen when he boards the Sea Lion to travel around the world with Runan, Holmes, Enteh, and Katri in the ending. If this does not occur, she accepts an invitation to live on Il Island.
Have Shigen killed before or at the Sealed Bridge in Map 24 to recruit her. She will appear with Shigen when Holmes meets up with Runan afterwards. She will also join in Map 31 when you visit one of the villages with Holmes or Shigen.
Sierra has sub-par growths and will result in her having lower stats than the rest of your attack Mages. Her Luck, Defense, Agility, and Skill are where she suffers most in comparison to her peers. Despite her statistics, Sierra sells herself as a useful ally with some unique abilities. She is effectively the only ally at your disposal with the Warp skill. This allows her to teleport to any maneuverable place on the map, allowing her to provide special support such as: protecting treasure chests, killing off thieves, healers, ballistae, opening doors earl, supporting recruitable allies, and providing the killing blow to an enemy which no-one else can reach. She is your only ally who can use Dark tomes, some of which are very useful and work well with Warp: Janura drains HP, Evil Worm and Tomaharn can attack from 3 spaces away, and Earthquake can attack all enemies on the map. She is a very useful character, but may need some stat-boosters to augment her stat growths or she may get herself into a dangerous situation pretty fast.
- Sierra is the only playable character in TearRing Saga: Utna Heroes Saga who can use dark magic.
- Unused dialogue in the game gives her an alternate backstory as the older sister of Meriah who is forced to work for Gwenchaos. After Sierra refuses to attack Meriah, Gwenchaos would turn on her and kill her with the ★Zahhak spell.