Lin Du

Biodata

Feature	Information
Name	Lin Du (林渡)
Species/Race	Wizard
Gender	Male
Affiliation	Hogwarts School of Witchcraft and Wizardry; Order of the Phoenix 5 31
Occupation/Role	Defense Against the Dark Arts professor; magical researcher 5
Status	Active
First Appearance	1

Background / History

Lin Du was orphaned and raised by an old wizard who recognized his exceptional magical talent. His master taught him everything he knew, including martial arts and talisman techniques. As a child, Lin Du learned quickly but was mischievous and prone to avoiding meditation, physical training, and careful talisman drawing; he would nevertheless comply when made to correct his work. His master's grave illness when Lin Du was sixteen ended that period of his life abruptly. 134

After graduating, Lin Du travelled globally in pursuit of magical knowledge. He returned to Britain two years before his discussion with Dumbledore because of its extensive Dark Magic literature and ruins, then attracted Ministry attention after triggering a trace spell in Wales. 29

He previously attended Hogwarts as a Chinese exchange student. During that year, he protected students from Death Eaters and studied Western magical systems, while McGonagall secretly aided his research by giving him an Undetectable Extension Charm dragonhide bag for Restricted Section notes. 2

When Aurors cornered him in a derelict London factory over his Dark Magic research, Lin Du disarmed and incapacitated them without seriously harming them. Dumbledore subsequently chose to bring him to Hogwarts as Defense Against the Dark Arts professor, both to protect him from Voldemort and to give his research structure and oversight. 1 5

Personality

Lin Du is intensely curious, analytical, and driven by a fear of aging and death. His research extends into forbidden subjects—including Unforgivable Curses, Fiendfyre, Horcruxes, Ancient Magic, and magical contracts—but he approaches them as problems to be understood rather than instruments of cruelty. 15 29 30

He is calm under pressure and confident enough to challenge Dumbledore's assumptions about powerful wizards. Although he identifies with Slytherin traits, Dumbledore judges his actions closer to Gryffindor: Lin Du ultimately rejects Horcruxes because they require murder and destroy the soul. 28 30

As a teacher, he is demanding but practical. He uses harsh, measurable exercises to develop students' spellcasting, endurance, and judgment, while remaining attentive to their safety. He dislikes excessive public attention and is visibly uncomfortable when Chao Feng's antics disrupt his composure. 63 94 95 157

Abilities & Skills

Defensive Magic and Duelling

Lin Du specializes in precise defense, evasion, and controlling the pace of a fight.

• Defeated several Auror squads while avoiding serious injury to them. 1 14
• Withstood the combined attacks of eight sixth-year students for three minutes, incapacitating all of them without being hit. 14
• Dueled Severus Snape to a stalemate, repeatedly neutralizing Snape's aggressive spells. 36
• Defeated Filius Flitwick and Minerva McGonagall in a two-on-one duel with Partis Temporus. 69

Dark Magic Research

Lin Du studies dangerous magic with unusual technical control and caution.

• Could not cast the Imperius Curse because he lacked pure malice toward humans. 15
• Practiced Fiendfyre, successfully containing a dangerous office experiment and later using it to destroy Voldemort's diary Horcrux. 19 23 31
• Developed Invoco Ventoculregem, a stable Fiendfyre vortex controlled through magical power and a rotational storm structure. 167
• Understands the soul-corrupting consequences of Horcrux creation and rejects their use despite pursuing longevity. 29 30

Ancient and Wandless Magic

Lin Du investigates the underlying structures of magic, oaths, and bindings.

• While petrified by the Basilisk, remained conscious and perceived the ancient magical traces of contracts, including his bonds with Chao Feng and Selene. 52
• Gained insight from Lady Ravenclaw's memories within the diadem and subsequently manipulated light without a wand or incantation. 82
• Demonstrated a wandless magical barrier. 90
• Uses Eastern talismans, including one that allows control of seawater. 94

Physical Ability

Lin Du possesses martial training and exceptional physical strength.

• Was trained in martial arts by his adoptive master. 134
• Repelled a Tibetan brown bear with a single punch in the Kunlun Mountains. 133

Teaching and Training

Lin Du is an exacting Defense Against the Dark Arts instructor and mentor.

• Introduced monthly examinations for Hogwarts students from third through seventh year. 14
• Co-founded Hogwarts' Duelling Club with Snape. 36
• Trained Harry Potter under Ministry magical suppression near Azkaban, combining spell drills, endurance training, and talisman-assisted sea exercises. 94 95
• Proposed using the magic-suppressing Pendant Box to train Cedric Diggory under adverse conditions. 141

Equipment / Weapons / Items

• Dragonhide bag — An Undetectable Extension Charm bag McGonagall gave him to store Restricted Section notes. 2
• Talismans — Eastern magical tools used for practical effects, including controlling seawater. 94
• American Iaijutsu — A magical sniper rifle designed by Lin Du; it fires mithril bullets and has an effective range of roughly 1,828 metres (2,000 yards). 90
• Mithril bullet — Ammunition for American Iaijutsu; Lin Du gifted one along with the rifle to Dumbledore. 91
• Pendant Box — A recovered artifact that suppresses magic and amplifies negative emotions. 141
• Felix Felicis — A Christmas gift from Snape. 159
• Unicorn-hair bracelet — A Christmas gift from Hagrid. 159
• Animagus transformation notebook — A Christmas gift from Sirius Black. 159

Relationships

• Albus Dumbledore — Mentor, employer, and occasional ideological opponent. Dumbledore invited Lin Du to teach at Hogwarts, trusted him with the Horcrux secret, and later enlisted him in the Order of the Phoenix. 5 28 31
• Minerva McGonagall — Former supporter and colleague. She assisted his studies during his exchange year and advocated for his appointment as professor. 2
• Chao Feng — Contracted spirit-beast companion and research partner. Chao Feng can communicate mentally, hide in shadows, deliver messages, and assume a powerful divine-beast form; their relationship is marked by sarcasm, mutual reliance, and occasional conflict. 5 23 52 95 157
• Severus Snape — Colleague and duelling rival. They co-founded the Duelling Club and fought their opening exhibition match to a stalemate. 36
• Harry Potter — Student and summer trainee. Lin Du agreed to train Harry, setting demanding goals under Azkaban's magical suppression and leaving Chao Feng to protect him during a trip to Paris. 91 94 95
• Selene — Cautious associate who offered information on “Transcending Death” in exchange for a Moonlight Vow. 19
• Helena Ravenclaw / the Grey Lady — Potential source of Ancient Magic knowledge. She offered information in exchange for Lin Du completing two tasks. 73
• Remus Lupin — Chosen by Lin Du as his assistant despite Lupin's werewolf identity; Lin Du also agreed to handle the Wolfsbane Potion issue. 111
• Cedric Diggory — Student whom Lin Du advises and trains for the Triwizard Tournament. 141
• Tenzin Phuntsok — Guide and travelling companion in the Kunlun Mountains; he came to respect Lin Du after witnessing his strength and magic. 133 137

Story Role / Major Arcs

Recruitment to Hogwarts

After attracting Ministry suspicion through his Dark Magic research, Lin Du is offered a protected position at Hogwarts. He accepts primarily because the school gives him access to research opportunities and a safer base from Voldemort. 1 5

Defense Professor

Lin Du establishes his authority by defeating his advanced sixth-year class, institutes monthly examinations, and co-founds the Duelling Club with Snape. His teaching reshapes student attitudes toward practical defense and earns him broad respect. 14 36

Horcrux and Basilisk Investigation

His Fiendfyre expertise enables the destruction of Voldemort's diary Horcrux. After being petrified by the Basilisk, Lin Du uses the condition to perceive the structure of ancient magical contracts, expanding his research into Ancient Magic. 31 52

Ancient Magic Research

Lin Du seeks Ancient Magic through Dumbledore, Helena Ravenclaw, Ravenclaw's diadem, and expeditions to the Guge Kingdom ruins in the Kunlun Mountains. His study grants him wandless manipulation of light and deeper insight into magical essence. 63 73 82 133 137

Harry Potter's Training

At Dumbledore's request, Lin Du takes Harry to the North Sea near Azkaban for intensive summer training. He uses the region's magical suppression, physical conditioning, and talismans to strengthen Harry's spellcasting and resolve. 91 94 95

Fiendfyre Innovation

After months of isolated research, Lin Du develops Invoco Ventoculregem, a controlled Fiendfyre vortex that embodies his attempt to impose order on one of the most destructive forms of Dark Magic. 167

Trivia

• Lin Du was unable to use the Imperius Curse specifically because he could not produce sufficient malice toward humans. 15
• Students mistakenly gave him a large chrysanthemum wreath after his recovery from petrification, misunderstanding its funerary significance in Eastern culture. 63
• Chao Feng once transformed into a muscular, unclothed imitation of Lin Du, much to Lin Du's distress. 157