Regulus

Biodata

Name	Regulus Black (雷古勒斯)
Alias(es)	Brother Regulus
Gender	Male
Affiliation	Black family; Slytherin House; Hogwarts School of Witchcraft and Wizardry
Occupation/Role	Hogwarts student; protector and collaborator of Lucretia
First Appearance	The Platform 9

Background / History

Regulus is a member of the Black family and Sirius Black's brother. Despite the strain between them, the brothers retain shared memories of studying astronomy and secretly stealing Uncle Alphard's Astrology Notes as children. Their relationship briefly warms while teaching Lucretia about the night sky. 46

He possesses knowledge inherited from the Black family, including ancient material-detection techniques, magical reference texts, and compass-based astronomy. 46 47 49

Personality

Regulus is usually gentle, warm, and attentive toward Lucretia. He notices her discomfort in crowds, shields her from hostile attention, helps with her belongings, and remembers small details about her interests. 9 10 17

Behind this mild manner, he is observant, mischievous, and willing to use intimidation or Dark Magic against those he considers threats. He monitors Pettigrew's suspicious interest in the Crouch family, confronts him after discovering the surveillance, and uses a Heartbreak Curse to ensure he cannot identify his attacker. 33 34

He often defuses tension between Little Barty and others, but also enjoys teasing Barty and Sirius over their feelings for Lucretia. 10 37 48

Abilities & Skills

Dark Magic

Regulus knows a Black-family variation of the Heartbreak Curse.

• Used the curse on Peter Pettigrew after learning he had been gathering intelligence on Lucretia and the Crouch family. 34
• The variation can leave its target disoriented for weeks and unable to identify the caster. 34
• He treats the curse as a deliberate warning rather than an impulsive attack. 33 34

Ancient Magical Detection

Regulus employs a Black-family method for locating magical materials.

• Examines physical texture and magical response before testing a target with wandlight and prepared reagents. 49
• Successfully identifies a special rock at the waterline, causing crystals to form across its surface. 49
• Collects the resulting crystals for Dumbledore's material-resonance exercise. 49

Advanced Transfiguration and Talisman Crafting

Regulus studies Transfiguration that preserves a material's original vitality rather than forcing a complete change.

• Consults Black family materials on preserving a material's essence during Transfiguration. 47
• Can balance the structural aspect of a living leaf-talisman transformation, though he initially struggles to retain the leaf's vitality. 47
• Combined his structural control with Lucretia's life-preservation magic and Little Barty's form control to create an Oval Amulet. 47 48
• Helped create an amulet that absorbs magical energy from incoming minor spells and resonates especially strongly with Lucretia. 48

Astronomy and Navigation

Regulus is knowledgeable about constellations and the use of Black family compasses.

• Teaches Lucretia to identify constellations, including Leo and its brightest star, Regulus. 46
• Uses a compass to guide astronomical study and explain Black family star lore. 46
• Knows concealed routes around Hogwarts and guides Lucretia and Little Barty away from Filch's patrols after curfew. 33

Equipment / Weapons / Items

• Wand — used for detection magic, Transfiguration, and the Heartbreak Curse. 33 34 49
• Personalized quill set — a gift for Lucretia; contains three sky-blue feather quills engraved with her initials, “L.C.” 10
• Dragonhide Gloves — gifted to Lucretia for her flying lessons. 17
• Black family compass and astronomy materials — used to teach Lucretia constellations and navigation. 46
• Black family Transfiguration booklet — contains material on preserving an object's essence during transformation. 47
• Detection reagents and crystal vial — used to locate and collect magical crystals. 49

Relationships

• Lucretia Crouch — sister figure. Regulus calls her “Sister,” protects her from unwanted attention, gives her thoughtful gifts, and works with her on potions, Transfiguration, and magical research. 9 10 17 47 48
• Bartemius “Little Barty” Crouch Jr. — close friend and Lucretia's fellow protector. They coordinate against Pettigrew, collaborate on magical projects, and regularly tease each other. 10 33 37 47
• Sirius Black — brother. Their relationship is tense but rooted in shared childhood memories and Black family traditions; Regulus engineers situations that allow them to reconnect. 34 46
• Albus Dumbledore — instructor and observer of Regulus's magical development. Dumbledore recognizes the dialogue-based nature of Regulus's inherited detection method and teaches him Guardian Perception. 49
• Peter Pettigrew — adversary. Regulus grows suspicious of Peter's inquiries into the Crouch family, confronts him, and uses a Heartbreak Curse after the surveillance is confirmed. 33 34

Story Role / Major Arcs

• Hogwarts arrival and support of Lucretia — Regulus meets Lucretia on the Hogwarts Express platform, comforts her amid public scrutiny, assists with her trunk, and protects her as they board the train. 9
• First-semester protector — He gives Lucretia a customized quill set and Dragonhide Gloves, reassures her about her unusual Transfiguration, and helps shield her from hostile Slytherin attention. 10 15 17
• Pettigrew surveillance incident — Regulus recognizes Peter's repeated inquiries and covert observation of Lucretia, then confronts him after the group returns from the Forbidden Forest. 33
• Temporary alliance against the threat — After Pettigrew's surveillance notes are discovered, Regulus supports a temporary alliance between Little Barty and the Marauders to protect Lucretia. 34
• Ancient magic studies — He joins Lucretia and Little Barty in researching living Transfiguration, crafting an energy-absorbing Oval Amulet, gathering magical materials, and learning Guardian Perception. 47 48 49
• Black brothers' astronomy lesson — Regulus brings Sirius and Lucretia together for a shared astronomy session, reviving memories of his childhood bond with Sirius. 46

Notable Quotes

“Some things shouldn't be pried into.” 33

“The Black family's ancient detection method... never fails.” 49

Trivia

• Regulus chose star-and-moon-patterned wrapping paper for Lucretia's quill set after remembering that she liked such designs. 10
• His name is shared with the brightest star in the constellation Leo. 46
• Although he often appears composed, Lucretia is unsettled by the colder expression he shows when preparing to deal with Pettigrew. 33