Sucy is a tall, thin girl who bears an image of a stereotypical witch. She has pale, grayish skin, mauve hair, and red eyes with white pupils. She comes off as laid-back, with droopy, half-lidded eyes that make her look indifferent or lethargic half of the time. Her left eye is covered by a large fringe of hair. Because of Sucy's pastel mauve tone, seeming lack of arms (her arms are only visible when she moves them), and a uniform which is longer than usual, that is reaching to the ground, she gives off an eerie aura and a ghostly appearance.
For pajamas, Sucy wears a white and red cap, paired a white long-sleeved collared tunic that reaches past her feet. She is occasionally depicted without arms in this outfit, although her arms are usually exposed whenever she's wearing this attire.
The early promotional poster of the original short film gives Sucy olive-green hair instead of puce, blue eyes, and a slightly darker skin tone.
When introduced in the short films, Sucy is portrayed as an aloof, calm, sarcastic and somewhat sadistic person. She also surprisingly remains indifferent in various situations and things that drive the other girls crazy, which shows that she is calmer than her roommates. She continues to display these characteristics in the anime, although she appears to be somewhat more apathetic.
As shown in "Sleeping Sucy" and other separate occasions, it has been suggested that even with her own kind, Sucy was considered an eccentric freak; she had a clear preference on something which scared or at least disturbed other girls, such as the idea of getting eaten, foul-smelling fumes of potions or poisons, performing experiments with potions and poisons on Akko, and pulling scary pranks that she found amusing, less so for her victims. Hannah and Barbara also refer to her as "Creepy Sucy" when they were picking on Sucy, Akko and Lotte. However, contrary to their belief, Sucy is neither a complete freak nor a heartless anti-social girl, as she does care a lot for her friends in spite of having no qualms about using them as test subjects in her potion experiments, whether or not they give consent to it. In addition to this, her other hobbies are shown to include yoga and meditation. It is also hinted that the only strong emotional connection she had was with Akko, which explains why the memory of their first meeting is her most cherished one. This was later confirmed in "Yesterday", where she went to the bridge when they first met when Akko was missing.
Abilities and Equipment
She has advanced knowledge of alchemy and is very skilled in creating potions. She has an uncanny interest for mushrooms, and uses them in most of her recipes, usually deadly or poisonous ones. For a young witch, she has vast knowledge of potions and poisons (including their effects), and is able to prepare poisonous potions that not only can kill its victims, but also is able to reduce said victims' bodies into caustic, liquid body mass. Some of her potions are even capable of causing explosions. She is also able to prepare fertilizer potions that accelerate the growth of vegetation, a potion that gives life to objects and a special Mandrake potion that temporarily increases magical power. She does all of this despite the fact that such potions are not allowed to be made at Luna Nova.
Notable potions she has in her disposal are:
- Festering Potion
- Poison Gas Potion
- Experimental Poison Gas Bomb
- Puppet Magic Potion
- Nutrient Potion
- Frog Leg Potion
- Memory Alteration Potion
- Explosive Powder
- Pyro Booster Potion
- Ultra Super Energy Drink Potion
- Weapon-Wand Fusion Powder
- Cactus Nutrients
In addition of her skills in potion brewing, Sucy is skilled in other forms of magical practices including broom flying, metamorphosis, Illusory, object control, and fusion magic. Like everyone in the Manbavaran family, she has developed immunity to poisons and toxins.
- Sucy's broom in the first episode is a Walis Tambo, a soft broom commonly used in households in the Philippines.
- Sucy's family is different in both the Terio Teri manga and in the Keisuke Satō manga. In the Terio Teri manga, she stayed with her biological family, whereas in the Keisuke Satō manga, she was adopted by an elder witch along with several other children who did not have any parents to take care of them.
- The latter case seemed to be partly inspired by the early concept of Sucy's intended backstory as shown in the official panel of Little Witch Academia at AnimeNEXT 2017. According to the said panel, Sucy was abandoned at an orphanage as a baby along with a vial of deadly poison, and thus all of her experiments are actually attempts to discover the said poison's formula and track down her original family with it.
- During the development of Sucy's background in 2013 film however, Sucy has a biological family as with in Teri Terio manga, but they are very poor that she also working part-time job as magic show assistant during her enrollment at Luna Nova while initially presented as an exchange student. As a reference to witches in Polynesian mythology, Sucy possesses a special ability to split her own body apart into pieces and control the said pieces however she wishes, an ability she exploited for the aforementioned part-time job. Owing to this, there's a running gag where her head will occasionally fall off in her daily life. Unfortunately, such concept eventually scrapped due to it will make her stands out more than Akko. 
- In the same development, Sucy was originally intended to be a "loser" and not as sharp-tongued as she is best known today. The reason why she also made a smart aleck is so there's a member of Akko's team who commented on Akko's actions.
- Sucy was born on December 31st, making her birthday on New Year's Eve as stated in Little Witch Academia Chronicles.
- Sucy makes an appearance in the eighth episode of Space Patrol Luluco, another anime series produced by Studio Trigger.
Her first name, "Sucy", can mean "holy" in Malay and Indonesian, and may also be derived from "Susi" in Filipino, which means "key"; while her surname, "Manbavaran", is apparently derived from "Mambabarang" in Cebuano, which means "warlock/witch" and "black sorcerer/sorceress".