Natsuki Subaru

Biodata

Feature	Details
Name	Natsuki Subaru (莱月昴)
Alias(es)	Little Cai / Cai (assumed identity) 931 943
Species/Race	Human; transmigrated Japanese boy 928
Gender	Male; can temporarily assume a female form through a learned skill 964
Affiliation	Emilia's camp; Roswaal's mansion
Occupation/Role	Mansion handyman; Emilia's supporter and knight 942 979
Status	Returned to his original world while retaining his abilities and equipment 1004
First Appearance	Chapter 924

Power Progression

Stage / Realm / Level	Chapter	Notes
Return by Death	929	Recognizes that death returns him to a prior save point while retaining his memories; his earliest loops leave him mentally exhausted.
Essence Berry-enhanced physique	927 928	Consumes foul-smelling Essence Berries, gaining noticeably greater strength and later continuing to use them as physical training.
Golden Apple enhancement	929	Obtains a golden apple that improves his stamina, senses, coordination, and physical ability toward superhuman levels.
Stubborn Blessing	937	Receives the blessing from Fang Mo; self-affirmation can reinforce his endurance, recovery, physical performance, and perception.
Tinkers' Construct Ring / Black Flame Dragon Envoy	938	Borrows Fang Mo's ring and releases the Black Karmic Fire of the End Dragon. The power initially engulfs him uncontrollably before he learns to endure and control it.
Shoggoth transformation	957	Uses the Shoggoth ring to merge with Black Tai Sui, gaining a monstrous body, regenerative support, and the strength to defeat magical beasts.
Spiritual Speech application	958	Discovers that his blessing can empower others through spoken affirmation, substantially strengthening Rem in battle.
Cangqi Ascends the Steps	982	Amplifies his pain to an extreme degree, pulls out his spine, and invokes an Otherworldly Evil God during his battle with Puck.
Stubborn Blessing III	987 991	The blessing reaches a higher stage, allowing him to distort perception and reality strongly enough to break Petelgeuse's possession and manipulate his judgment.
Evolved Black Tai Sui	994	After consuming the Great Rabbit and Petelgeuse, Black Tai Sui develops new properties that Subaru begins to investigate.

Background

Arrival in Lugunica

Subaru arrives in Lugunica wearing an out-of-place tracksuit and initially expects the world to follow the conventions of the isekai stories he knows. His first encounters instead involve poverty, street thugs, fatal violence, and repeated resets at Fang Mo's fruit stall. He realizes that his apparent “golden finger” is Return by Death after dying several times in rapid succession. 924 928 929

His early loops are dominated by fear and confusion. After consuming Essence Berries to become stronger, he defeats the thugs who had beaten him and joins Emilia in searching for her stolen badge. His attempts to save Emilia, Felt, and Old Man Rom repeatedly end in Elsa Granhiert murdering everyone present. 928 929

Fang Mo's Influence

After discovering that Fang Mo is also an outsider who treats the world like a game, Subaru tries to win his trust by pretending to be Chinese and adopting the name “Cai.” Fang Mo becomes an erratic mentor and older-brother figure: he tests Subaru harshly, but also gives him equipment, teaches him skills, and eventually accepts the truth of Return by Death. 930 931 946

At Roswaal's mansion, Subaru works as a handyman in hopes of becoming someone Emilia can rely upon. His repeated week-long mansion loops retain his learned skills but erase everyone else's memories, leaving him isolated and increasingly afraid that he cannot prove what he has suffered. 942 943 945

Curse and Mabeast Incident

Subaru investigates the curse placed on him in the village and identifies the dog responsible. When village children are taken into the forest, he fights beside Rem against a mabeast horde. Rem's distrust turns to sympathy after seeing Subaru's concern for the children and his willingness to protect her. 954 955 956

After being badly injured and buried by the beasts, Subaru activates Fang Mo's Shoggoth ring. The Black Tai Sui enters his body, restores his breathing, and transforms him into a monstrous combat form. Subaru saves Rem, defeats the mabeast leader, and later discovers that his spoken self-affirmations can strengthen her as well. 957 958

Royal Capital and Witch Cult Conflict

Subaru accompanies Emilia to the Royal Capital as her supporter. He later defeats Julius in a duel through a combination of the Shoggoth and Copper Coin Sword, earning recognition while avoiding Fang Mo's planned clash with Reinhard. 969 970

After witnessing a disastrous future in which Emilia, Rem, and Fang Mo are lost, Subaru returns to an earlier point and decides to prepare for the Witch Cult and Great Rabbit attacks himself. He uses Wilhelm's attachment to Theresia to secure cooperation, exposes Roswaal's involvement in the crisis, defeats the Great Rabbit with Black Tai Sui, and destroys the Witch Cult's local forces. 981 983 985 986 987 994

Subaru confronts Petelgeuse Romanee-Conti, counters the Invisible Hand, survives possession, and uses Stubborn Blessing III to convince Petelgeuse to offer himself to the Shoggoth. He then burns Roswaal's Book of Wisdom and helps Wilhelm eliminate the remaining Witch Cultists. 989 990 991 994

Return to His Original World

When an apparent exit becomes available, Subaru chooses not to abandon the people of Lugunica before securing their future. Fang Mo later departs, entrusting Emilia and Rem with Subaru's Copper Coin Sword and asking them to care for him. 998 1003

Fang Mo eventually sends Subaru back to his original world, where he reunites with his parents. Subaru initially suspects the reunion is an illusion, but proves that he still possesses his otherworldly power by manifesting Dragon's Breath. 1004

Appearance

Subaru initially wears a modern tracksuit that immediately marks him as an outsider in Lugunica. Later, Fang Mo gives him a festive red Taoist robe, which becomes his more distinctive outfit. 924 958

• Carries a black ring associated with Black Tai Sui and black-flame power. 938 957
• In Shoggoth-merged combat form, black flames, eyes, teeth, mouths, tongues, and other grotesque features manifest across his body. 988
• His feminization skill transforms him into a long-haired, black-haired young woman while retaining the red Taoist robe. 964
• The feminized form manifests a short Copper Coin Sword made from three coins bound with red thread. 964

Personality

Subaru begins as a shut-in, chuunibyou teenager who expects to become an effortlessly powerful isekai protagonist. Repeated deaths destroy that confidence, but they also force him to become observant, cautious, and capable of using information gathered across loops. 929 931

He is deeply attached to Emilia and later develops an equally strong bond with Rem. His desire to save people is sincere, even when he recognizes that it sounds arrogant or impossible. He rejects Fang Mo's suggestion to identify a culprit by killing different people in separate loops, preferring to find a solution he can accept himself. 945 946

Subaru becomes markedly more decisive after the Witch Cult disaster. He can be ruthless toward enemies such as Roswaal and Petelgeuse, but his decisions remain centered on protecting Emilia, Rem, and the ordinary people endangered by the conflict. 985 986 991

Abilities & Skills

Return by Death

Subaru's defining ability resets the timeline after his death, returning him to an earlier save point while preserving his memories.

• Allows him to retain knowledge gathered during failed timelines. 929 945
• Reset points can update as he advances; after clearing the mansion crisis, he returns to a recent point in the Royal Capital rather than the original fruit stall. 969
• He can eventually activate a reset directly through a system interface rather than dying. 976 977
• His learned skills and proficiencies persist across resets, preventing him from relearning the same abilities. 943 983
• The ability imposes a severe emotional burden because only Subaru remembers the people and experiences erased by each loop. 929 946

Stubborn Blessing

A blessing that converts Subaru's conviction into temporary physical, mental, and supernatural effects.

• Accelerates recovery from minor wounds when Subaru insists that they do not hurt. 942
• Can enhance strength, speed, durability, sensory perception, and combat evasion through self-affirmation. 953 954
• Lets him locate aspects of his curse by testing how physical contact affects his body. 954
• Its effects have limits tied to his mental state, understanding, and conviction; declarations alone cannot grant limitless power. 954
• At Stubborn Blessing III, it can influence others' beliefs and distort reality enough to overcome Petelgeuse's possession. 991

Spiritual Speech

A discovered extension of Subaru's blessing that applies empowering declarations to other people.

• Reinforces Rem's physical strength during the mabeast battle. 958
• Can be directed at allies through exaggerated praise and confidence rather than self-directed statements. 958
• Subaru later applies the same principle to ease Wilhelm's pain. 974

Black Tai Sui / Shoggoth

A living black mass given to Subaru by Fang Mo, capable of merging with him or returning to its ring.

• Repairs and replaces damaged bodily tissue, clears mud from Subaru's lungs, and supports rapid recovery. 957
• Transforms Subaru into a powerful, multi-mouthed monster capable of tearing apart mabeasts. 957
• Can consume large numbers of enemies, including the Great Rabbit horde, but leaves Subaru mentally drained when recalled. 987
• Gains new properties after consuming the Great Rabbit and Petelgeuse. 994
• Its influence is mentally dangerous; controlling or recalling it can feel like Subaru's consciousness is being gnawed away. 991

Black Karmic Fire

The destructive black flame released through Fang Mo's Tinkers' Construct Ring.

• Can wither surrounding terrain and erase incoming ice attacks. 938
• Provides area-clearing power against the Great Rabbit and Witch Cultists. 987 988
• Subaru initially loses control of the flames and is engulfed by them himself. 938
• He can manifest the same Dragon's Breath after returning to his original world. 1004

Forbidden and Shadow Arts

Fang Mo teaches Subaru several dangerous techniques beyond conventional magic.

• Cangqi Ascends the Steps — requires extreme physical and mental pain to summon an Otherworldly Evil God. 937 982 991
• Desire Blasphemy — a mental-pollution technique used as a ranged attack and later adapted to mimic Petelgeuse's authority. 953 990
• Poisonous Brain Erosion — creates blood clots in an opponent's brain; Subaru uses it against Petelgeuse. 989
• Veil of Shadow Magic — can obscure Subaru's appearance, though he accidentally reveals his feminized form during a duel with Julius. 983

Feminization Skill

A bug-like transformation skill taught by Fang Mo.

• Changes Subaru into a female form with long black hair. 964
• Materializes the Copper Coin Sword as its associated weapon. 964
• Subaru views the skill as an embarrassing but potentially useful route to greater power. 964

Equipment / Weapons / Items

• Tinkers' Construct Ring — A dark-purple ring made from Manyullyn, Wither Metal, and Ender Metal; grants black-flame power, magical resistance, physical resistance, and a Wither effect. 938
• Shoggoth Ring — Holds Black Tai Sui and enables Subaru's monstrous transformation. 950 957
• Copper Coin Sword — A three-coin sword bound in red thread, manifested through Subaru's feminization skill; can also be used as a Coin Whip. 964 987
• Red Taoist Robe — A Chinese-style outfit given by Fang Mo after the mabeast incident. 958
• Suona — Given by Fang Mo before his departure, alongside instructions to keep practicing it. 1003

Relationships

• Fang Mo / Xie Dongwen — Initially Subaru's killer and tormentor at the fruit stall, then his mentor, benefactor, and self-styled older brother. Fang Mo teaches him skills, believes his Return by Death, and repeatedly urges him toward self-reliance. 924 946 983
• Emilia — Subaru's first major attachment in Lugunica. He joins her search for the stolen badge, supports her Royal Selection bid, and openly declares his wish to become her hero; Emilia later admits that she loves him. 929 938 1003
• Rem — Initially attacks Subaru because of his Witch's aura, but comes to trust him after the village crisis. She saves him, shares her trauma with him, and declares that he is her hero. 943 957 958 1003
• Ram — A mansion maid who initially monitors Subaru and remains wary of him, but later works alongside him and Rem during the Witch Cult crisis. 954 985
• Wilhelm van Astrea — A strategic ally whom Subaru recruits by using Theresia's reunion as leverage. They later cooperate to eliminate Witch Cult remnants. 985 994
• Roswaal L. Mathers — An antagonist who knows of Subaru's resetting ability and deliberately engineers suffering to reshape him. Subaru defeats and interrogates him, then burns his Book of Wisdom. 986 992 994
• Petelgeuse Romanee-Conti — The Archbishop of Sloth responsible for Subaru's worst future timeline. Subaru defeats him, endures his possession, and ultimately has the Shoggoth consume his spirit. 981 989 991
• Natsuki Kenichi and Natsuki Suiko — Subaru's parents, who reunite with him after Fang Mo sends him back to his original world. 1004

Notable Quotes

“I… I, Natsuki Subaru… am going to be Emilia-tan's great hero!!!” 938

“This time, I don't want your help. I want to kill all of them myself...” 983