Shaula (シャウラ) is a humanoid Demon Beast and the apprentice of the Sage, Flugel. Mentioned throughout the series due to being confused for her master, she formally debuted in Arc 6 as a secondary antagonist for the first half and climax as well a supporting character during the middle portion.
Tasked with guarding the Pleiades Watchtower, she initially acted as an obstacle toward Subaru and his companions. However, she later took a neutral stance when they started taking the tower's trials. Unfortunately, after the rules were violated, she transformed into her Demon Beast form and attacked them due to her contract. In the end, she was turned into a tiny scorpion and is currently in Meili's care, as she is instinctively attracted to her Divine Protection.
Shaula had green eyes with three additional red dots around her pupils and long blackish brown hair which she wore tied together in what she referred to as a scorpion tail. She was tall and had a model physique along with a large chest, all in all, being a very attractive woman. She only wore a black bikini-bra, a bow-tie, a necklace, black hotpants accompanied with an orange belt, and a tattered black-and-orange cloak, which were of the same colour pallet as Natsuki Subaru's outfit.
When she took the form of a colossal scorpion, Shaula had a jet black body, glowing red eyes and sharp pincers, which could be detached at-will. She also had a long tail with a stinger at the end of it. When entering her Attack Hue phase, her colour gradually shifted from jet black to blood red.
Shaula has mentioned that Flugel and her mother were the ones who blessed her with her "design".
After her defeat in arc 6's climax, Shaula transformed into a small crimson red scorpion. As of the end of arc 6, it remains unclear whether or not the change is permanent though it is stated that at this point, she retains no human traits whatsoever, effectively making her a tiny Demon Beast.
Shaula is described to be like a girl at the bottom of a girls caste who runs errands for others. She is absolutely loyal to Flugel, however, she tends to be thoughtless so she is unfit for mental work. Also, she is unable to tell people apart and therefore refers to Subaru as her teacher based on smell alone as he appears to smell the same as Flugel.
Despite her usual empty-headed, unconcerned manner, Shaula has been shown to show deep emotion in certain situations. Namely when she concealed the existence of the fifth rule of the tower in an effort to spend more time with Subaru. She also stated she'd easily kill Emilia and others if Subaru said so, hinting at the fact she only cares about Subaru. She even told that if Subaru were to ask her to die, she would be willing to kill herself, and went as far as to beg him to order her to do so before it was too late while she started transforming into a scorpion, in order to avoid killing her beloved master against her will.
At the end of Arc 6, Shaula completely lost her humanity and became a small red scorpion Demon Beast. She acts solely according to her instincts, as seen when she instinctively latches herself onto Meili, as she is heavily attracted to her by her Divine Protection of Magic Manipulation, which calms her down.
Shaula was created by the Witch of Gluttony Daphne, along with help from the Sage Flugel, for currently unknown reasons, serving as the Sage's apprentice.
400 years before the main story, Shaula, Flugel, Reid and Volcanica fought, defeated and sealed off the Witch of Envy Satella. After the triumphant battle, Flugel decided to give all his credit to Shaula for an unspecified reason. Some time after, the two of them planted a seed in the middle of the Lifau Highway; a seed that would later grow into a giant tree dubbed Flugel's Tree. She later helped Flugel build the Pleiades Watchtower, where she remained for the past 400 years, acting on the Sage's orders and watching over the Evil Sealing Stone Shrine.
Immense Strength: Shaula is able to lift an Earth Dragon and a Dragon Carriage with ease and carry them around.
Transformation: Any time a rule of the tower is broken, Shaula automatically becomes aware of it and is then forced due to her contract, to unwillingly transform herself into the form of a colossal scorpion Demon Beast or more commonly known as the Crimson Scorpion, loosing her will in the process, she will then instinctively act and try to eliminate everyone in the tower as a "cold-blooded killing machine" without paying attention to the damages done. This allows her to fire stingers at people with tremendous speed, as well as giving her the ability to attack people with her pincers. Her pincers are able to easily bisect a person in two and the stingers can be fired in rapid successions and are capable of decimating a fully grown Earth Worm mid air. In addition, she can detach her pincers and use them as a detonator device which are triggered when the target wanders too close. In this form, she possesses regeneration, as shown when she regenerated her tail after it was cut off. Shaula can partially transform her hand into a pincer for the means of attacking.
Hell's Snipe (ヘルズ・スナイプ Heruzu Sunaipu): Shaula is able to connect her needles and her target together with mana and release it as if it's gravitating toward them. It is fast, powerful, and is able to be fired rapidly. The immense power is easily able to snipe a person's head clean off, erase a Hungry Horse King's entire body from existence by showering it with projectiles and blowing people's limbs off without them even being aware of the incoming attack. It is worth mentioning that the needles are stated to be enchanted with magical powers and to carry high heat, meaning that Hell's Snipe may be a spell of Yang magic nature, though not confirmed.
- Infinite Hell's Snipe (インフィニティッド・ヘルズ・スナイプ Infinitiddo Heruzu Sunaipu): An advanced version of Hell's Snipe, Shaula is able to summon countless white magic circles, which can then be used to simultaneously shot many needles in rapid succession towards her desired target(s).
Immense Power: Shaula is mentioned to be strong enough that she can even force Reid Astrea to use both hands while in combat once every ten times. Subaru also mentioned she could potentially be more difficult to deal with than the Sin Archbishops themselves.
- Shaula, also known as Lambda Scorpii, is the second-brightest star in the southern constellation Scorpius.
- In Arabic, Shaula (شاولا) means stinger, which also refers to the star's position on the Scorpius constellation.
- Tappei confirmed that Shaula is a Demon Beast created by Daphne.
- Shaula was familiar with slang only known by people from the 21st century earth, as she can be observed using terms such as "Ok Google" while fighting the Demon Beasts. It's currently unknown how she's familiar with these phrases.
- She survived all those excruciating four centuries solely on Demon Beast meat. The meat is stated to have a disgusting taste and is nigh inedible, so when she ate Emilia's cooking, she confessed that it was better than Demon Beast's meat, and was impressed by Shaula's words about her cooking.
- According to the author, Shaula was almost the last of the main characters to appear 
- Shaula has her own named chapter in both the web novel and in the Light Novels.
- "Does Master, want me to die? Hmm, if it's Master's request then I'll listen to anything, and I'm perfectly fine with it personally, but again, isn't it quite a weird timing for such a thought?" Arc 6: Chapter 70. Section 2.
- "Please tell me to die... If you do that, I will, for Master..." Arc 6: Chapter 70. Section 2.
- "Yeah, yeaaah! I'm the Stars-Keeper! If a rule violation happens, I will become a cold-blooded killing machine who you will all be scaaared of!" Arc 6: Chapter 37. Section 1.
- "I don't know the small details, but it was firing long and narrow needles enchanted with magical powers. The needles carried high heat, probably the effect of firing magic." Arc 6: Chapter 13. Section 4.
- ''She was almost the last main character'' AskFM Q&A