Xiao Cui

Biodata

Feature	Details
Name	Xiao Cui (小翠)
Alias(es)	Katsuki Riri; “Katsuki Rurusu” (a fabricated “long-lost little sister” identity); Magical Girl ☆ Xiao Cui; Emerald Storm 208 254 403 534
Species/Race	Magical Girl 208
Gender	Female
Affiliation	Wind City Squad; associated with the 22nd Group through Doctor 208 254
Occupation/Role	Magical girl; middle-school student; commander of the Little Sprite army 408 751
Status	Active
First Appearance	Chapter 75

Power Progression

Stage / Realm / Level	Chapter	Notes
Little Sprite Summoning	79, 209	Commands emerald Little Sprites in combat. Each sprite costs 1% of her magic power to summon; summoning roughly one hundred at once would exhaust her to unconsciousness.
Remote Sprite Network	224, 320	Develops brooches that let authorized users summon a Little Sprite and allow Xiao Cui to monitor them through its senses. The sprites are revealed to possess their own mana and independently cast spells.
Expanding Sprite Army	316, 324, 333	Can create a new Little Sprite every few minutes and improve their forms; 3% magic power produces staff-wielding “bishop” sprites rather than ordinary spike-bearing units. Given sufficient preparation time, their numbers could resist an Extinction Formula.
Extinction Formula Awakening	333, 427, 429	Her summoning formula is identified as an Extinction Formula. While critically injured, she activates Mortal World · Fairyland and enters Fairyland; the formula is later identified as “This World’s Extinction Formula.”
Global Deployment	399, 403	Begins leaving Little Sprites throughout the human world, including hundreds in New York, so she and authorized allies can summon forces without rebuilding an army from scratch.
Gate Control and Spatial Transit	613, 617–618	Under Chi You’s instruction, opens the Gate to Fairyland and learns nearly seamless travel between Fairyland and reality. Her spatial transitions surpass Chi You’s in speed, though she initially cannot stop safely and lacks close-combat skill.
Fusion-Enhanced Sprites	791	Following completed Fusion, her magic power rises dramatically and the Little Sprites undergo metamorphosis. They remain vulnerable to certain high-output Scale Powder attacks.

Background / History

Xiao Cui was abandoned at the Green Mountain Elm Crystal Lake Orphanage without any identifying information about her biological parents. She was later raised in Fusha Village by adoptive parents whose actions left her with deep resentment toward the Katsuki surname. 209 447

When her adoptive parents turned themselves in and were imprisoned, Cong Yu offered to take Xiao Cui with him. Yaochuan Guang agreed to care for her, bringing Xiao Cui into the household that would become her real family. 76 Cong Yu and Yaochuan Guang had previously stopped her from attacking her adoptive parents, an intervention that likely prevented her from becoming a villainous magical girl. 302

As a magical girl, Xiao Cui initially hid her connection to Cong Yu’s household and the 22nd Group. Her visits to Doctor, where she studied spellcraft and discussed her loneliness after awakening, were eventually exposed by Cong Yu through her schedule and intelligence trail. 208 209 254

Appearance

Xiao Cui is a young-looking magical girl with a fairy-tale-like appearance that matches the Little Sprites she commands. Her transformed magic power is emerald green. 534

• Long emerald-green hair. 456 534
• Large jade-green eyes. 534
• Youthful, petite build. 101
• Often accompanied by tiny emerald Little Sprites carrying spikes or staffs. 324 534

Personality

Xiao Cui is exceptionally observant, calm, and mature for her age. Cong Yu describes her as someone who can infer whether people are good or evil and anticipate where events are heading from limited information. She approaches combat as a detached observer, processing battlefield intelligence through her Little Sprites and making pragmatic decisions quickly. 241 245

Her usual indifference originated as a defense mechanism against her childhood circumstances. Although she initially tried to preserve goodwill toward others, repeated betrayal and attempts on her life hardened her judgment; she activated her Extinction Formula in fury and resolved to reserve kindness for the people she truly cared about. 434 446

Despite this ruthlessness, Xiao Cui remains deeply attached to her found family. After the orphanage confirmed that no information remained about her birth parents, she accepted Cong Yu, Yaochuan Guang, and the others as her family. 403 447 She is also conscious of the danger of becoming accustomed to killing and has expressed a desire to stop. 400 435

Abilities & Skills

Little Sprite Summoning

Xiao Cui summons Little Sprites through an exclusive spell formula tied to her inner self and family history. The sprites are independent magical beings rather than simple disposable constructs. 209 320

• Summons cost a fixed 1% of her magic power per Little Sprite. 209
• The sprites persist without continuous magic-power consumption after they are summoned. 316
• Their strength rises alongside Xiao Cui’s magic power. 209 750
• They can scout, harass, form defensive lines, fight with spikes and staffs, and cast spells independently. 320 324
• Individual sprites are initially weak and depend on numbers, coordination, and preparation time. 324 395
• Barriers can prevent outside sprites from reaching her, forcing her to rebuild her force from scratch. 395
• High-durability enemies capable of breaking through the swarm are particularly dangerous to her. 434 535

Sprite Command and Shared Senses

Xiao Cui can command large numbers of Little Sprites while sharing their senses, turning them into a distributed intelligence network. 224 245

• Processed visual information from more than thirty sprites simultaneously during battle. 245
• Used Little Sprite surveillance to uncover a plot to kidnap Nagashima Koki. 409
• Can authorize trusted allies to command an Elf Tree that produces Little Sprites in her absence. 444
• Uses her worldwide deployment plan to maintain an army ready for immediate local summoning. 399 403

Mortal World · Fairyland

Xiao Cui’s Little Sprite formula is an Extinction Formula connected to Fairyland, the sprites’ homeland. She is classified as an Extinction Corruption Overcomer for resisting its corruptive influence. 429 611

• Opens Gates between Fairyland and the Present World. 613 617
• Can use Fairyland for rapid repositioning and near-instantaneous spatial travel. 617 618
• Her formula poses a catastrophic risk: if its host dies, an Extinction Formula can continue cycling as an eternal disaster. 672
• Xiao Cui consciously avoids activating its full destructive potential recklessly. 429

Tactical Analysis

Xiao Cui’s intelligence is a major part of her combat strength.

• Rapidly identifies enemy intentions, vulnerabilities, and battlefield priorities. 241 395
• Uses provocation and misdirection to separate stronger groups of enemies. 395
• Analyzed the political structure around Wind City’s great families and exposed a hidden bodyguard’s divided loyalties through sprite surveillance. 408 409
• Directs reinforcements and manages battlefield resources under pressure. 751

Close-Combat Limitations

Xiao Cui can fly or reinforce her body with magic power for movement, but close combat is her weakest area. 376 618

• Her spatial movement initially left her unable to stop safely. 618
• Chi You identified close-combat training as her next major area of improvement. 618
• Her usual strategy is to maintain distance behind Little Sprite defensive lines. 535

Equipment / Weapons / Items

• Little Sprite Brooches — Brooches Xiao Cui helped develop that allow a wearer to call a Little Sprite by shouting her name; Xiao Cui can immediately monitor the wearer through the summoned sprite. 224
• Little Sprites — Her primary combat force, reconnaissance network, and means of long-distance influence. 209 399

Relationships

• Cong Yu — Guardian and older-brother figure who removed her from Fusha Village, supports her training, and protects her when others seek to exploit or seal her. Xiao Cui asks him to watch over her for a lifetime. 76 435 447
• Yaochuan Guang — Guardian and sister figure whom Xiao Cui calls “Mom” after returning exhausted from the United States. They support one another in battle and at home. 76 403 751
• Doctor — Mentor and collaborator at the 22nd Group. Doctor studies Xiao Cui’s formula, teaches her spell principles, and later helps her with operations and combat planning. 209 287 689
• Nagashima Koki — Close friend and frequent partner. Xiao Cui protects Koki during monster attacks, works with her on investigations, and trusts her with control of an Elf Tree. 444 457 488
• Chi You — Extinction Formula mentor. Chi You teaches Xiao Cui to control the formula as an instinct and invites herself into the Wind City Squad after Xiao Cui asks her to live with them. 612 613
• Red — Instructor and trusted senior who teaches formulas alongside Doctor; Red also repairs Xiao Cui’s legs after a failed high-speed spatial-travel landing. 612 618
• Takemikazuchi — Protective companion who chose to look after Xiao Cui. The two share a “Beverage Alliance” and regularly try drinks together. 254 432 573

Story Role / Major Arcs

• Fusha Village and adoption — Xiao Cui is left without care after her adoptive parents’ imprisonment and joins Cong Yu and Yaochuan Guang’s household. 76
• Wind City Squad growth — She becomes a recognized magical girl of the Wind City Squad, builds a growing Little Sprite force, and earns public attention for her summoning ability. 266 333 344
• Extinction Formula crisis — After being nearly killed by the 17th Group, she activates Mortal World · Fairyland. The revelation that her Little Sprites are an Extinction Formula brings the Church’s scrutiny and threats of confinement. 427 429 434 435
• Judgment Descends — Xiao Cui assists Cong Yu in purging AHM and corrupt American officials, personally carrying out executions with her Little Sprites and becoming internationally known as Magical Girl ☆ Xiao Cui. 399 403
• Fairyland training — Chi You trains her to master Fairyland Gates and use her Extinction Formula rather than being controlled by it. 612 613 618
• Later battles — Xiao Cui uses her army and intelligence network against Angels, Scale Powder, and threats targeting magical girls across multiple regions. 535 750 751

Notable Quotes

“Infinite Sprites, come forth!” 434

“My sight can see many things, but it seems I never saw myself. So I’m very happy.” 447

Trivia

• Xiao Cui cleared a difficult platform-jumping game at Wind City High School’s festival and set a record beyond the gaming club members. 180
• She defeated Tereido repeatedly at chess despite having never previously been seen playing it. 302
• She pulled the ultra-rare Elf King · Xiao Cui card, whose listed stats are 52 Attack, 99 Defense, and 99 Tactics. 368
• She enjoys White Flower Snakegrass Water, a drink Takemikazuchi finds revolting. 573