Eris

Biodata

Feature	Information
Name	Eris Boreas Greyrat (艾莉丝)
Alias(es)	Mad Dog; Red Lion 89 295
Species/Race	Human 466
Gender	Female
Affiliation	Boreas Family; Sword God Style Main Dojo; formerly the Water God Style Advanced Dojo 296 431
Occupation/Role	Swordswoman; Allen Boreas Greyrat's student and younger sister 134 607
Status	Active 607
First Appearance	Chapter 87

Power Progression

Stage / Realm / Level	Chapter	Notes
Beginner, Sword God Style	128	Began as a beginner swordswoman; learned that aura externalization—and thus Flow Arcana—required reaching the Advanced Swordsman level. 128
Advanced Swordsman	178	Successfully imbued her sword with Fighting Spirit, gaining the ability to project it around her blade. 178
Advanced Sword God Style / intermediate Water God Style	295	Defeated Falz Eurus Greyrat with advanced Sword God Style, while applying Water God Style techniques including Lifted Hammer. 295
Chief Disciple, Water God Style Advanced Dojo	296	Recognized as the Advanced Dojo's chief disciple after defeating Falz and rallying the other apprentices. 296
Swordmaster	433	Completed the Swordmaster Trial, defeated seven young Sword God Style swordsmen, and overcame Nina Falion; crowned the youngest Swordmaster. 431 432 433

Background

Eris is the daughter of Philip and Hilda Boreas Greyrat and the granddaughter of Sauros. Her blood connection with Allen manifests as an instinctive familiarity between the siblings long before their relationship is fully understood. 135 192

As a child, Eris attended noble school but was mocked by other students, fought frequently, and was ultimately expelled. Her education remained severely incomplete: she could initially write only her own name and treated basic arithmetic as repeated “equal shares.” 121 122

She accepts Allen as her master after Ghislaine indicates that he is stronger than she is. Allen subsequently builds her training around Sword God Style while using Thought Flow and Water God Style principles to address its weaknesses. 106 134

Appearance

Eris is a red-haired, red-eyed swordswoman with sharply upturned eyebrows and an openly defiant expression. Her hair is repeatedly compared to red paint or flame. 160 431

• Long, dark-red to wine-red hair. 431
• Fiery red or reddish-brown eyes. 89 128
• Distinctive upturned eyebrows shared with Allen. 205
• Wears a simple swordsman's uniform while training in the Sacred Land of Swords. 431
• Becomes taller and more mature after two years of intensive training. 601 607

Personality

Eris is loud, proud, confrontational, and intensely competitive. She instinctively takes the dominant position in relationships, once telling Sylphy that she “allowed” her to be a friend because she did not fully understand friendship as an equal bond. Despite the awkward phrasing, her gesture was sincere. 89

She is straightforward to the point of bluntness and prefers fighting to extended discussion. Her impatience with lessons, especially arithmetic and literacy, contrasts with the discipline she brings to sword training. She is highly responsive to praise from people she respects, particularly Allen, Ghislaine, and Sauros. 121 126 298

Eris's central motivation is to stand beside Allen as an equal. After his disappearance, she interprets his departure as a search for stronger opponents and devotes herself to becoming someone he can take seriously. 391 432

Abilities & Skills

Sword God Style

Eris's primary discipline is the Sword God Style, for which she possesses exceptional instinct and combat talent. She favors direct, decisive attacks and develops the Sword of Light into her defining technique. 130 432

• Uses the three core Sword of Light stances, including upper stance, middle stance, and iaijutsu-based drawing attacks. 134 432
• Uses Iai Slash as an opening attack and can defeat multiple opponents in rapid succession. 432
• Defeated Nina Falion by prioritizing the essence and momentum of the Sword of Light over rigid form. 433
• Killed Sword Saint Anzo Moreira after enduring his superior Fighting Spirit and identifying his openings. 606

Fighting Spirit

Eris can imbue and project Fighting Spirit through her blade, marking her advancement to Advanced Swordsman. 178

• Reinforces strikes, kicks, and movement with Fighting Spirit. 295 296
• Uses Fighting Spirit to stabilize herself during high-speed movement and while driving Rudy's Magic Car. 431
• Can use a Fighting Spirit-infused hand to disrupt opponents' weapons and balance. 432

Water God Style and Thought Flow

Though not naturally suited to Water God Style, Eris studies it under Allen to compensate for Sword God Style's predictability and to improve her ability to read combat information. 134 293

• Uses Water God Style techniques such as Pluck, Lifted Hammer, and Horizontal Display. 295 298
• Applies Thought Flow to respond to incoming attacks and force opponents into mistakes. 134 605
• Uses Water God Style observation to discern hostile intent and counter attacks from blind spots. 432 605
• Has not mastered Flow Arcana despite her other progress. 298

North God Style Techniques

Eris incorporates practical North God Style elements into her movement and close-quarters combat. 298

• Uses the Fighting Spirit principles of the Four-Legged Form without placing her hands on the ground. 298
• Employs kicks, knee strikes, and irregular movement to disrupt more orthodox swordsmen. 295 433

Magic

Eris receives basic magic instruction from Rudeus and can cast Water Ball. 130

• Quickly learned the Water Ball Spell.
• Initially lacked control over its size and power, repeatedly soaking the group during practice. 130

Equipment / Weapons / Items

• Sword — Uses wooden swords for dojo challenges and training, and carries a steel blade in actual combat. 294 302 605
• Wind-element Magic Tool — Absorbed much of an attack from Orsted during the Raleigh Town conflict. 469
• Magic Car — Uses Rudy's Magic Stone-powered car to travel through the Sacred Land of Swords, driving it recklessly at high speed. 431

Relationships

• Allen Boreas Greyrat — Older brother, master, and the person Eris most admires. Her goal is to become strong enough to stand shoulder-to-shoulder with him. 134 251 432 607
• Ghislaine Dedoldia — Sword God Style mentor. Ghislaine trains Eris's fundamentals and supports her growth without allowing Allen's exceptional ability to damage her confidence. 130 431 298
• Sylphiette — Friend. Eris initially struggles to express friendship properly but comes to value Sylphy's company and praise. 89 298
• Rudeus Greyrat — Tutor and companion. He teaches her literacy, arithmetic, and basic magic, though Eris often challenges his patience. 121 122 130
• Hilda Boreas Greyrat — Mother. Hilda teaches her noble etiquette and ballroom dancing, patiently adapting lessons to Eris's swordsmanship-based way of thinking. 165 167
• Philip Boreas Greyrat — Father. His decision to bring in tutors gives Eris her first sustained peer relationships and formal instruction. 87 192
• Sauros Boreas Greyrat — Grandfather and primary childhood role model. His praise strongly motivates Eris to continue studying. 108 127
• Isolte Keruel — Fellow swordswoman and Water God Style associate. Isolte recognizes Eris's talent and later travels with her. 220 464
• Nina Falion — Sword God Style rival. Eris defeats Nina during her Swordmaster advancement. 433
• Anzo Moreira — Human God Cult leader and Sword Saint whom Eris kills after he dismisses her mixed sword style. 605 606

Story Role / Major Arcs

Arrival at Boreas Manor

Eris arrives to assess Allen as a potential tutor, initially causing confusion by mistaking Rudeus for Allen and slapping him. She soon accepts Allen as her master after learning of his strength. 87 106

Education and Early Training

Under Allen, Rudeus, Sylphy, and Ghislaine, Eris studies literacy, arithmetic, etiquette, dancing, magic, and swordsmanship. Her academic progress is slow, but her enthusiasm rises when instruction is connected to practical combat or praised by her family. 121 122 165

Water God Style Dojo Challenge

In the Royal Capital, Eris challenges Falz Eurus Greyrat and the Water God Style branch dojo. Her victory establishes her as the Advanced Dojo's chief disciple and reignites the apprentices' competitive spirit. 293 295 296

Sacred Land of Swords

After Allen's disappearance, Eris trains relentlessly in the Sacred Land of Swords, believing she must become strong enough to find him and stand at his side. She completes one thousand daily swings, passes the Swordmaster Trial, and defeats Nina Falion. 391 431 432 433

Human God Cult Pursuit

Eris travels alone in search of the Human God Cult, despite continued difficulty reading maps and place names. In Nolles Town, she kills cult members, fights through more than twenty guards, and defeats Sword Saint Anzo Moreira. 601 605 606

Reunion with Allen

Allen locates Eris after the battle with Anzo. Despite his altered appearance, she recognizes him through their familiar dynamic and rejoins him for a return to the Sacred Land of Swords. 607

Notable Quotes

“I, Eris Boreas Greyrat, will be as strong as my brother!!” 251

“Who else wants a piece of me?!” 296

“Then I shall become that person! I want to become an opponent my brother can take seriously!” 432

Trivia

• Eris's favorite way to plead for something is a Boreas-specific cat-like “meow” gesture. 153 156
• She once had no idea what the Boreas family crest looked like. 160
• She learns ballroom dancing quickly when Allen explains the steps through swordsmanship analogies. 165
• Despite becoming a Swordmaster, she continues to struggle with reading maps and written place names. 601