Born into the noble class of the Fibel Family', Sistine has lived a great life of prestige because of the success of her lineage.
When Sistine was younger, she promised her grandfather that she would unravel the mysteries of the Melgalius' Sky Castle. Her grandfather's death fueled her desire for learning and honing her magic skills.
At some point, Rumia Tingel came to live with the family. It was mentioned they didn't get along in their first meeting but soon came to love each other as sisters.
A New Instructor Edit
Sistine travels through town to school with her friend and foster sister Rumia Tingel, they discuss the new teacher for their class. While walking, they are surprised by a running man who screams at them to move causing Sistine to use magic which causes him to fall into a fountain and emerges in an eccentric manner. Despite this, Sistine apologizes for her action which is further accredited the man's arrogant behavior. When the man notices Rumia, he seems to recognize her but Sistine throws him in the sky with her magic and he falls in the fountain again.
The two girls make their way to school where they are shocked to discover that the man from earlier Glenn Radars is their new teacher but he is very lazy and doesn't bother to teach, instead choosing to sleep. This goes on for a few days and Sistine is annoyed by his lack of motivation and his disrespect to her, a noble's daughter.
She soon gets fed up with him and challenges Glenn to a magic duel, though worried he would win, she is surprised by his slow magic chants and easily defeats him. This still doesn't change his teaching methods as he still lazes about in class, much to her frustration.
When he had insulted magic by stating it is merely a tool used to kill, she slapped him and ran out of class crying, stating that she hated him. That night, she reflected on her past with her late grandfather and remember what drives her to pursue magic.
The next day, she was very surprised at a new display, it was Glenn not only showing up to class on time but genuinely apologizing to her for his previous words. Glenn stated that while he still detested magic, he acknowledged he went too far in his statement before apologizing once more. He actually started teaching, causing Sistine and her class to learn new ways of magic. Days go by, with Glenn continuing with lectures and becoming popular that even students of other classes sneak in to listen. Sistine realized Glenn deceived her by acting like a slacker when he was really skilled as an instructor and wondered what brought about this development in him. Despite this change, he still acts immaturely towards her as he gave her more books to carry than Rumia after they offered him help and when he erased a chalk writing of the lecture, just to spite her after she asked for him not to do so. She soon asked him about the difference in his treatment towards her and Rumia, he explains that Rumia is sweet while she is quite cheeky, much to her irritation. Through this, she realized that even though he was terrible in manners he was actually competent, forcing her to begrudgingly accept what a good teacher he was.
One day, two criminals barge into the class and Sistine is terrified at threatening the class to kidnap Rumia. She tries to stand up to them and is nearly killed but Rumia gives herself up telling Sistine that she believes Glenn will save her though they are told he is dead, much to their disbelief. After Rumia is taken, Sistine is then thrown into the room by Jin Ganis with the intent to force himself on her. She tries hold her stance by using her family name but breaks down, as the man strips her and prepared to carry out the act, just as Glenn (who was still alive) arrives in the room interrupting him. He nearly leaves, though she tells him to save her from being assaulted as he belatedly realizes the situation. When Jin tries to attack, she warns Glenn, but he ignores this however, Jin couldn't attack, due to Glenn revealing a spell on a card that blocks off magic. Sistine is amazed but it is short-lived, since it works on him as well, but this feeling returns when she watches as he effortlessly overpowers the man in hand-to hand combat, defeating him.
Sistine was then freed by Glenn who hinted at some of his past but Sistine stopped him by pointing his pants being down, to his dismay. Glenn soon tied up Jin as Sistine was put off by how he did so as Glenn discovered Jin's alignment with the Researchers of Divine Wisdom just as Celica contacted him. Sistine watched as he informed Celica of the situation and they discuss what to do next, with Celica being at a conference and the portal to the school destroyed; Glenn knew he had to take action.
After she informed Glenn that Rumia was taken, he was confused as to why they went for her just as a crying Sistine tried going after her but Glenn stopped her since she'd be in danger as well. Sistine then tearfully agreed with Glenn's previous statement about magic but he comforted her and told her he'd kill the other criminals to save Rumia.
His statement causes Jin to awake and laugh, telling Sistine that Glenn is no different from him or his comrades pointing out his feat in taking him down. At that moment, a portal opens with living skeleton who attack Glenn who can barely stand against them until Sistine provides help. With that, Glenn destroys a majority of them as he and Sistine retreat as Jin taunts them before he is killed by the skeletons. Sistine is horrified as Glenn tells her they have no obligation nor time to save the criminal before he tells Sistine to use a spell for him. When she states she can't do so, he tells her she can if she listened to him but does threaten to dock her grade, to her dismay.
After Glenn destroyed all the skeletons, Reik confronted Glenn and Sistine with swords enchanted in magic. Sistine was asked if she can perform a certain spell but she replied negatively as Glenn (literally) pushed Sistine out of the way as he prepared to engage Reik.
Managing to use her magic to stop some of the fall, Sistine landed safely and wondered what Glenn was trying to do. She soon heard an explosion and was worried she'd be a hindrance before realizing Glenn's strategy after noting he asked about her power.
Sistine arrived just as Glenn was stabbed multiple times and started to use a chant to deactivate the spell, as Sistine helped him in dispelling the magic in the swords as Reik realized Glenn tossed Sistine aside as a strategy to catch him off-guard. The criminal tried to activate his swords again but Glenn used The Fool's World to deactivate his magic and stabbed Reik with one of his blades that was without magic, killing him.
With Reik finished, Glenn moves to go save Rumia as Sistine implores him to rest because of his injuries though he ignore her before he collapses from his wounds as Sistine worries for him and takes him to the infirmary as he wakes up being tended to by Sistine. He briefly reprimands her for her continuous use of healing magic but is told by the worried girl, it was needed to save him and he rests once more. Sistine then watches Glenn talking in his sleep of wanting to be a mage of justice until he wakes up again to find Sistine asleep.
Very soon, Glenn went off to find Rumia and saved her from Huey Lysen (Sistine's former teacher and secret mole for the Divine Wisdom). A month after the incident, Glenn became a full-time instructor of the class as Sistine and Rumia come to him for aid on a lecture he gave. Sistine is also embarrassed when Rumia hints she wanted partial credit for helping him in stopping the incident but she shrugs this off.
Magic Games Edit
Sistine and Rumia went to Glenn for help on the magic competition but he shrugged them off and told them to handle it themselves.
The two went to class and tried getting some to enter the contest but nobody wanted to enter and humiliate themselves in front of the Queen.
Glenn then shows up in the classroom and says he'll help them get members, as Sistine brings up his recent disregard of this but he ignores this and tells them he'll make the decision of who joins as she prepares for a headache. However, Glenn surprises her with his declaration of leading the class to victory as he starts his selection method, which earns surprise and protest from many of them until he gives his reasons since there are events which are best suited for a few.
As he went on with his selection, Sistine was surprised as she noted that Glenn had actually been paying attention to the class as he recognized their habits and talents. Sistine realized that he had a different side to him besides just being a slacker. However, she unknowingly ruins a possible change of plans because of a disagreement with Gibul Wisdan who had suggested another plan.
When she finds Glenn and Halley Astry making a wager of three months of salary on their class winning, she intervenes by agreeing to the bet on Glenn's behalf as well as threatening to report Halley to the board if he caused any more trouble which forces him to leave after accepting the bet. She got her class to be excited with Glenn's belief and told him she somewhat saw him in a new light for his acts as he thanked her (though was internally worried), which Rumia commented on.
Days go by where Sistine along with Rumia observed their teacher, as he readied the class for the games. Sistine was teased for her amazement with Glenn's methods but defended herself by stating she wishes he could be like that in regular days.
During the games, Sistine watched as her class succeeded in the games in events Glenn selected, this caused her to ask Glenn if he planned all this out as he confirmed it.