Mei

Biodata

Feature	Details
Name	Raiden Mei (芽衣) 160
Alias(es)	Raiden Queen 176
Gender	Female
Affiliation	ME Corporation; St. Freya Academy 161 231
Occupation/Role	Valkyrie; former orphanage volunteer, cook, and caretaker 161 179
First Appearance	9

Power Progression

Stage / Realm / Level	Chapter	Notes
Honkai Energy manipulation training	171	Learns under Reanna and demonstrates fine control by manipulating a thread ball.
Raiden Queen — first safety threshold	176	Activates Liu Bai's belt, manifests purple lightning and a lightning-forged katana, and remains in control.
Raiden Queen — second safety threshold	176	Breaches the second failsafe; her armor changes and massive oni-like gauntlets form around her.
Third output stage	177	Reaches an average output 1.2 times that of the original Pseudo-Herrscher, with maximum output exceeding 1.4 times.
Herrscher of Thunder	265	Fights Sirin while she possesses Kiana's body.
Veteran Herrscher	551	Her full-power Honkai Energy output surpasses that of Bella, the former pseudo-Herrscher of Thunder.

Background / History

Raiden Mei is the daughter of Raiden Ryoma and the young lady of ME Corporation. At fifteen, Ryoma began leaving her at Reanna's orphanage on weekends so she could make friends; Mei quickly became a beloved older-sister figure through her poised manner, cooking, and care for the children. 160 161

At the orphanage, Mei met Bronya and Seele, who were three years younger than her. She maintained a close, sisterly role with both girls, while also learning more about her father's identity as the possible Houmu Sword Saint. 160 161

Mei possesses exceptionally high compatibility with the Gem of Conquest. Edison proposed an exoskeleton built around the gem, while Liu Bai agreed to create a basic detachable God Key for her and arrange training to control her Honkai Energy. 165 Under Reanna's guidance, Mei began practicing direct Honkai Energy manipulation before receiving Liu Bai's transformation belt. 171 176

Appearance

Mei has purple-black hair and is commonly seen carrying a katana or wearing the belt that regulates her Herrscher power. 176 399

• Raiden Queen form — Purple lightning surrounds her body; horn-like protrusions emerge from her forehead. 176
• Manifested weaponry — Can form a lightning-forged katana and enormous oni-like gauntlets. 176
• Combat equipment — Received a custom-made katana from Cocolia after returning to ME Corporation. 254

Personality

Mei is polite, graceful, and attentive to others. Her conduct and cooking won over the orphanage children, who came to regard her as their dependable older sister. 160 161 She can also be shy and hesitant when discussing her feelings for Liu Bai, despite wanting to take the initiative. 167 168

In battle and crisis, Mei can become decisive to the point of being radical. Her Raiden Queen transformation suppresses her hesitation and cowardice, shifting her demeanor toward a colder, more imposing state. 176 642 She has also used the belt to make decisions when she is uncertain, including retrieving Ryoma after he ran away from home. 231

Abilities & Skills

Herrscher of Thunder

Mei controls lightning-based Honkai Energy through her exceptional compatibility with the Gem of Conquest and Liu Bai's regulation belt. 165 176

• Activates a controlled Herrscher-like transformation without immediately losing herself to Honkai Energy. 176
• Generates lightning, a lightning katana, altered armor, and oni-like energy gauntlets. 176
• Entered Herrscher mode to engage the Judgment-class Honkai Beast Benares. 263
• Fought Sirin while Sirin possessed Kiana's body. 265
• Her transformation affects her temperament, making her feel as though she has discarded hesitation and cowardice. 176

Honkai Energy Control

Before her full transformation, Mei trained in precise Honkai Energy manipulation under Reanna. 171

• Can make fine adjustments to controlled Honkai Energy constructs. 171
• Demonstrated enough aptitude to create a thread doll during training. 171
• Knows of eighteen mainstream Honkai types. 177

Swordsmanship

Mei uses a katana and possesses the Raiden family's inherited Hokushin Ittō-ryū techniques. 186 586

• Demonstrated orthodox Hokushin Ittō-ryū secret techniques before Hokushin Mei. 586
• Her proficiency with those techniques was judged comparable to Hokushin Mei's own. 586
• Uses Purging Thunder, though it once unexpectedly took the form of a kitchen knife rather than a katana. 186

Cooking and Caretaking

Mei is an accomplished cook and used her skills to care for the orphanage children. 161

• Became accepted by the orphanage children after preparing food for them. 161
• Her cooking is a point of contrast with Dr. Mei, who is notably poor at it. 180

Equipment / Weapons / Items

• Transformation belt — A device made by Liu Bai to regulate and release Mei's Honkai power in stages. 176
• Gem of Conquest — The source of her unusually high Honkai compatibility and thunder-based power. 165 176
• Custom katana — A katana made for her by Cocolia. 254
• Purging Thunder — A weapon Mei handles through her swordsmanship; its manifested form can vary unexpectedly. 186

Relationships

• Liu Bai — Mentor, adoptive brother, and the focus of Mei's romantic feelings. Mei initially struggles to confess to him, later becoming far more open about pursuing him. 167 168 535
• Raiden Ryoma — Her father and a highly protective daughter-con. Mei eventually recognizes his likely identity as the Houmu Sword Saint. 160 176
• Bronya Zaychik — Younger-sister figure from the orphanage; Bronya recognizes Mei's authority as an older sister. 160 161 236
• Seele Vollerei — Younger-sister figure whom Mei met at the orphanage; Mei remains protective of her, including toward Dark Seele. 160 168 253
• Kiana Kaslana — A classmate who persistently tries to become close to Mei. Mei considers Kiana a friend, though she also finds her bothersome. 235 236
• Rita Rossweisse — Initially clashed with Mei during the Sky Dome City incident; Rita defeated Mei and secretly placed a tracker on her. 9 14
• Dr. Mei — A Previous Era scientist who closely resembles Mei but is a distinct person. Their resemblance creates mutual insecurity and rivalry. 179 180
• Cocolia — An ME Corporation associate who treats Mei like family and gifted her a custom katana. 254
• Edison — Helped devise Mei's Gem of Conquest control plan and proposed a dedicated training laboratory. 165

Story Role / Major Arcs

• Sky Dome City incident — Mei confronts Rita alongside Theresa and Bronya's group, trying to delay Rita after becoming enraged over Kiana. Rita defeats her and attaches a tracker without her knowledge. 9 14
• Orphanage period — As ME Corporation's young lady, Mei volunteers at Reanna's orphanage, becoming its admired “Sister Mei” and forming bonds with Bronya and Seele. 160 161
• Gem of Conquest training — Her compatibility with the gem is identified, leading to Honkai Energy training and the development of Liu Bai's transformation belt. 165 171 176
• St. Freya enrollment — Anti-Entropy sends Mei and Bronya to St. Freya Academy, where Mei adjusts to Valkyrie life and meets Kiana. 231 233 235
• Return to ME Corporation — After being captured while returning home with Bronya, Mei reunites with Edison and Cocolia and receives her custom katana. 254
• Destiny Headquarters battle — Mei transforms to confront Benares, then fights Sirin in Kiana's body as the Herrscher of Thunder. 263 265

Notable Quotes

“Perhaps there are some changes, but to me, it's more like I've discarded hesitation and cowardice.” 176