Kain

Biodata

Feature	Information
Name	Kain Eugene (凱恩)
Alias(es)	Akai; Kane
Species/Race	Human
Gender	Male
Affiliation	Imperial Knight Order; Hero Squad; Lionheart Society
Occupation/Role	Hero; knight; disciple of Sword Saint Eugene
First Appearance	Chapter 33

Power Progression

Stage / Realm / Level	Chapter	Notes
Mountain Style Sword Qi, first layer	296	Learns Eugene Sword Saint's inherited Mountain Style; at this stage, Sword Qi can be attached to his blade.
Mountain Style Sword Qi, second layer	365	Breaks through during his match against Mel. Sword Qi can cover his whole body and penetrate Mel's Magic Shield without breaking it.
Mountain Style Sword Qi, fourth layer	634	Develops the style's penetration and heavy-damage effects; challenges Mel to another spar.
Level 69	736	Nears Level 70 after fighting demon swordsmen on the front lines, but struggles to progress further.
Level 80; Mountain Style Sword Qi, seventh layer	767	Reaches Level 80 after months of severe training under the masked swordsman later associated with the Sword Apostle.
[Sword Storm] training	767, 772	Is taught the Level 100 sword skill by his masked instructor and later passes its Sword Qi fundamentals to Mel. He is warned not to use its full form before Level 100.
Elf King merge; Elf and Nature power	915	Completes training in Elf City, summons the Elf King to merge with himself, and gains both Elf-race Strength and a portion of Nature's power.

Background

Kain grew up as a beggar after fleeing a border village. He admired the knight En Edwin, whose example diverted him from becoming a thief. After drawing the Sacred Sword, he was taken in by Sword Saint Eugene, who allowed him to choose the name “Kain” and trained him as the Empire's Hero. 33 375 634

Eugene's training was strict but supervised. Kain was not sent to fight monsters as a six- or seven-year-old; when he was later exposed to combat and killing, Eugene remained ready to intervene. 314

As the Hero, Kain was cultivated to be an upright public symbol for the Empire: a knight without visible flaws who could represent humanity's hope in a dark age. This upbringing later conflicts with his origins and personal beliefs. 327 634

Appearance

Kain is a chestnut-haired young knight. His heroic status and Imperial Knight Order uniform make him highly recognizable at the Royal Academy. 364 407

• Chestnut-colored hair. 364
• Commonly fights with a sword and Sword Qi. 364 365
• Has trained shirtless during monster-hunting expeditions. 385

Personality

Kain is earnest, straightforward, and deeply loyal to the people he cares about. His upbringing as a Hero gives him a strong sense of responsibility, but he does not easily separate duty from compassion. When Lily is believed to be in danger, he leaves the front lines despite knowing the consequences for his position and squad. 649

He is diligent and receptive to stronger opponents. Defeat by Mel drives him to seek real combat experience, train against stronger monsters, and continue improving rather than resent his friend. 385 371

Kain can be uncertain when his identity as the Empire's Hero conflicts with his past as a commoner. He hesitates when Mel proposes overthrowing the nobility, yet ultimately refuses orders to fight humans and chooses to flee with Mel rather than oppose him. 634 751

Abilities & Skills

Mountain Style Sword Qi

Kain inherits Sword Saint Eugene's Mountain Style Sword Qi, a lineage-based style optimized through generations of Sword Masters. It emphasizes penetration, sharpness, and heavy damage. 296 634

• At the second layer, Sword Qi covers his entire body rather than only his weapon. 365
• Can pass through magical defenses; his sword wounds Mel through an intact Magic Shield. 365
• At four layers, allows him to cut through the shell of a rock beast far above his level. 657
• His Sword Qi reaches the seventh layer after training in the past. 767
• Even at equal Sword Qi layers, the inherited Mountain Style proves stronger than less-refined self-created styles. 571

Sacred Sword

Kain was recognized by and drew the Sacred Sword, making him the Hero and Eugene's chosen successor. 33 757

• Suppresses demon magic strongly enough for Kain to kill a demon swordsman. 736
• Is used against the giant rock beast when Kain needs every advantage to protect Lily and escape. 657
• Appears unable—or is believed unable—to be used against humans, a conviction central to Kain's refusal to fight in a human war. 751
• Cannot fully protect him from the mysterious woman who abducts Lily; it only partially nullifies her abnormal effect. 659
• Mel warns Kain that the sword may be alive and could influence its wielder. 373

Sword Storm

A Level 100 sword technique taught to Kain by the masked swordsman during the time-displacement incident. 767 772

• Kain can study its Sword Qi component before meeting the level requirement. 772
• Attempting the complete technique before Level 100 risks being consumed by its storm. 767
• Kain teaches its fundamentals to Mel. 772

Elf and Nature Power

Following his Elf City training, Kain gains power associated with the Elf King and Nature. 915

• Summons the Elf King and merges with him to enhance his abilities. 915
• Gains a pronounced life aura that counters Lich-type enemies and disrupts their regeneration. 915
• Uses a simplified ultimate sword technique alongside [Sword Qi Draw Slash] to defeat the Lich King. 915

Equipment

• Sacred Sword — Heroic sword drawn by Kain; especially effective against demons. 657 736
• Iron sword — Used during his spar with the masked swordsman in the past. 758
• White mask — Worn while moving through the Carlos Empire era, where he and Mel avoid revealing their identities. 770

Relationships

• Mel Carlo — Childhood friend, training partner, and eventual fellow fugitive. Kain trusts Mel's character even after the Empire brands him a criminal, though Mel's rapid growth repeatedly pushes Kain to train harder. 320 385 751
• Eugene — Kain's master, the Sword Saint who named, raised, and trained him as the Hero. Their relationship is strained when Kain defies the Empire and leaves with Mel. 33 751
• Lily — Kain's love interest. He abandons the front lines to search for her, reciprocates her confession, and continues seeking the strength to save her after her abduction. 649 658 736
• Felicia — Saintess and Hero Squad companion. She first meets Kain after healing him following a cultist-stronghold raid. 232
• Xi Edwen — Rival swordswoman and Lionheart Society associate. She initially attacks Kain over his name, but later trains and adventures alongside him. 296 385 388
• Sword Apostle / Masked Man — Mysterious Mountain Style master who imprisons, spars with, and harshly trains Kain after the chrono-teleportation incident. 757 758 767
• Luke Ronan — Mage selected by Kain for the Hero Squad based on intuition after witnessing his Mimicry Magic. 708
• Long-eared Archer — Squadmate who accompanies Kain from the front lines to Exar and helps him delay the giant rock beast during Lily's rescue. 649 657

Story Role / Major Arcs

Academy and Sword Qi Development

Kain enters the Royal Academy as the Empire's Hero and develops Mountain Style Sword Qi through training and competition. During the Class A team match, he remains the last member of his side standing and advances to the second Sword Qi layer while fighting Mel. 364 365

His loss to Mel exposes the limits of relying on a higher Sword Qi layer alone. Rather than withdrawing, he trains harder, hunts stronger monsters, and gains practical experience with the Hero Squad. 366 385

Hero Squad Formation

Kain attempts to build a balanced Hero Squad capable of facing the Demon King. He seeks a durable Knight and a Mage, unsuccessfully approaches Claire and Liberia, and later recruits Luke Ronan as the squad's Mage. 587 588 708

He also joins Mel and Xi Edwen in forming the Lionheart Society as a counterweight to the Brotherhood at the Royal Academy. 388

Lily's Disappearance

When Kain receives an indication that Lily is in danger, he leaves the demon front line and travels toward the Dragon Mountain Range with the long-eared Archer. 649

He reunites with Lily after fighting a powerful rock beast, then accepts her confession and promises to choose her. The moment is interrupted when a mysterious woman abducts Lily and overwhelms Kain despite the Sacred Sword. 657 658 659

Defection from the Empire

As the Empire falls into crisis, Kain is ordered to fight humans. He refuses, believing the Sacred Sword should not be used to spill human blood, and chooses to run away with Mel rather than obey the First Princess. 751

The two escape the Imperial City together, with Mel specifically prioritizing Kain's safety during the pursuit. 752 753

Chrono-Teleportation and the Carlos Empire Era

Azuk's chrono-teleportation magic separates Kain from Mel and sends Kain ten thousand years into the past, where he is imprisoned in the Imperial Palace as an alleged assassin. 756 757

There, a masked master of Mountain Style Sword Qi releases and trains him through repeated brutal spars. Kain advances to Level 80, reaches the seventh Sword Qi layer, and learns the foundations of [Sword Storm]. 758 767 772

Elf City Training and Return to War

Kain later seeks an Elf Tree contract as part of his Knight advancement, pursuing the Elf Knight route rather than the inaccessible Holy Knight or difficult Dragon Knight paths. 788

After emerging from Elf City, he defeats the Lich King using his new Elf and Nature power, then returns to aid the war effort. He wounds the Sky Apostle, forcing the Apostle to retreat, and is later persuaded to visit Lily in the Dragon race's mountain prison. 915 916 917