Falla wears sandals with red ribbons wrapped around her lower legs and ankles. Her skirt is a large leaf that's wrapped around her hips, with there being no underwear of any kind worn underneath, and she wears a bra made of purple petals with green straps. She has red eyes and short dark hair, and her butterfly wings are black with the segments being purple while having red spots adorning the edges.
The skirts she and her sister wear appear to change from time to time, with some instances described as it being a single large leaf to others when the clothing is made of multiple leaves. This suggests that they have different skirts they wear rather than the same type all the time.
Falla has a more witty and calculating mindset than her joyful and sporadically insane sister. As all giant butterflies do she relies on her beauty and sharp tongue to get her way as opposed to using magic or strength, both of which she possesses none of, and knows how to use what she has to great effect. Growing up Falla learned the ways of their people with likely top marks in her classes so that she could one day trick a man into being with her, or tie him up if it came down to it. This isn't to say Falla is a cold or cruel monster at heart, as she genuinely cares about her people and especially her sister. She simply followed their people's ways of life with firm dedication and practice and became a fine example of how sneaky and untrustworthy giant butterflies could be.
Living up to the pun of her name, Falla - Fallacy, this giant butterfly is the embodiment of what giant butterflies are like in Eden, at least when she's first encountered by Daniel and the others. She's an expert liar with a poker face that can't be cracked, and is a skilled trickster when it comes to deceiving potential targets. She's a master when it comes to bondage in which she can even tie herself up in a convincing manner, and can even tell when others are lying almost every time, a skill that makes it nearly impossible for others to deceive her themselves.
Even after joining Daniel's harem and learning the error of her ways she still retains much about her race's tropes, with her still telling small lies occasionally to get out of doing work or to place the blame for something she did on someone else, and using her sexual allure to entice Daniel and the other girls. However she has put her skill as a living lie-detector to good use for Daniel and their family as they often turn to her if they suspect someone is lying to them, knowing that she of all people would be able to tell.
Falla is first found by Daniel in what appears to be a trap she fell into by traveling witches. Although her story of being cursed seemed odd it was difficult to argue with given how she was bound and defenseless after recently seeing witches nearby. Her ruse quickly falls apart when Luna rushes to her thinking her sister is truly cursed, and doesn't stop crying until Falla confesses it was all just a trick to get to Daniel. Although spared from harm by the girls with Luna begging they don't hurt her Falla refuses to give up on Daniel and continues to chase after him with her sister in tow. Upon finding Daniel and his girls cursed by a nightmare and about to die Falla is only concerned with saving Daniel until Luna begs her not to be so evil to others. With Luna's help she's able to wake up the girls and in turn help wake Daniel before any of them die, and then goes right back to her hounding of Daniel which prompts her to be pushed away by them yet again.
Later she and Luna come across Emily, and although uneasy at first with being near a human child as that's a good way of inciting an angry mob of humans to come after her, she plots a way of getting closer to Daniel by helping the child find refuge and acting the hero. During the trip however Luna and Emily become separated from Falla and she quickly becomes fearful for her sister's life. Having nobody else to turn to she enlists the help of Daniel and his girls, who agree to help not for her but because they like Luna and want to help Emily. Although the ruse of her only wanting to help Emily so she could lower Daniel's guard becomes known so does her deep affection and care towards Luna which helps paint her in a better light. When their search brings them to Eston Falla uncovers Jovian & Jacqueline's true identity from remembering Emily's description of dangerous monsters that attacked her and warns everyone before its too late. Later when the gemini get their hands on Daniel and prepare to torture him in front of his girls Falla uses her cunning to trick the gemini into letting her get closer in a ruse that she'll rape Daniel in front of his girls to torture them that way. Instead she grabs Daniel's dagger and attacks the gemini, freeing Daniel and flying him back to his girls. After the ensuring fight with the gemini and then being told to leave the town by Charlotte the group finds Luna and discovers that not only was Emily a witch but she also raped Luna out of twisted love. Falla is instantly mortified and feels guilty for leaving her sister with the witch in the first place.
While still skeptical of Daniel's beliefs Falla agrees to help him gain an audience with her monarch at Luna's persistent insistence. It's there in Flairwood that they discover that princess Complica has been kidnapped and speaking to her mother is not possible. While Triska sets off in search of the princess the girls learn about Daniel's practice with magic and how he brought forth his power from a desire to protect them, even from Jovian & Jacqueline if it came down to it, and that included protecting Falla and Luna, something that stuns Falla from hearing. Meanwhile Triska manages to find and save Complica from swarm with Pip's magic, however a few swarm are accidentally brought along with them back to Daniel and the others, one of which that grabs hold of Falla and tries to fly off with her. Without thinking twice Daniel quickly leaps to her rescue and kills the swarm before it can kill Falla. Afterwards everyone learns of how Complica being kidnapped was because she told a lie to humans which backfired on her, one that led to her being permanently scarred with ripped wings. Seeing firsthand how lying only leads to trouble for her kind and learning that Daniel would fight to keep her safe because he genuinely cares about her, Falla becomes a firm believer of Daniel's beliefs and quickly falls in love with him. She even goes so far as to declare her devotion to Daniel in front of her monarch and back up his claims that they need to listen to him or else all giant butterflies could be doomed by their own false words.
Falla's personality changes during the course of the series. When first seen she's a sneaky manipulator only interested in raping Daniel and not caring about him or the other girls at all. After learning the error of her ways she changes into a devoted follower of his belief while seeing the other girls in a better light. She can still be counted on to tell a lie or two and will openly make snarky remarks, but she does learn to genuinely care and love Daniel and the girls as her new family.
Falla's aura manifests as a sense of cunning when called upon by Daniel. Her insignia is blowing wind to the left in purple light. When drawn by Daniel his sense of self-confidence and cunning increase, though this has only been stated by how Daniel feels as he has yet to use this power in any situation as of the latest book. He also gains the ability to control the wind to a small degree. When combined with Luna's aura he's able to create powerful gusts that can knock away a succubus or deflect a barrage of incoming longswords.
Falla's role in the harem is more of a supportive one. She's either seen with her sister as she's always keeping an eye on Luna to make sure she's staying out of trouble or to double up their allure towards Daniel, or being the sharp ear who catches any lies being told to the group. She's also the one who frequently translates for Squeak using their antennae.
When engaging in their group lovemaking sessions she tends to favor Squeak as her partner when not with Daniel. She appears to greatly care for Squeak despite how they used to fight in the past with her attempts to steal Daniel away, something which likely is why they have a strong bond now.
When officially accepted into Daniel's harem Luna and Falla are seen to willingly have sex with not only the other girls but each other as well, seeming to ignore their familiar status with one another both because they're co-mates for Daniel and also as a means of arousing him with their immoral love.
Falla's fetish is being tied up with bondage play. Although she's a master with tying others up it excites her to be the one being bound in rope. This seems to play into her submissive side which often comes out when Squeak is carrying or holding her.
- Falla's character and appearance is brought into Chronicles of Eden from a fanfiction the author has written for Rosario+Vampire, "Rosario Vampire: Brightest Darkness". In the fanfiction she doesn't have bug antennae and is actually a chronofly monster type.
- (to Squeak) "Yeah, squeak squeak squeak squeak. That's interesting and all, but in case you didn't know, I don't speak squeak."
~Act III, Ch.8
- (about Luna) "Who wouldn't care about their own sister? She is the biggest pain in the ass, and has ruined many chances for me to get pregnant by now, but dammit, she's my sister, I love her. I really wish I didn't at times, but I do."
~Act IV, Ch.1
- "We have no magic, no real strength, nothing but our beauty and cunning to get a man's seed. So that's what we do, we lie. We lie and say whatever we have to in order to get the man to mate with us."
~Act V, Ch.3
- Falla: "I never thought humans like him existed, I never thought anyone like him could be real. But he proved me wrong; he showed me that humans can love monsters, real love! ...If you want to keep him from me then you're just going to have to kill me!"
Act V, Ch. 12
- "My sister and I both have what no other giant butterfly does back in Flairwood, and I promise you that having a man genuinely love you makes all the difference in the world."
Act VII, Ch.7
- (to Squeak) "Tell me, how is it that even though we're both girls, different species even, and that I can't understand a word you say. . . why is it I love you so much?"
~Act VII, Ch.8
- "I was the top of my class when it came to deception, something I'm not proud of but I will admit."
~Act VII, Ch.11