Friend or Foe, you never get used to it, do you…? People dying that is.

—Sephiria Arks

Sephiria Arks
Biographical Information

セフィリア アークス


Sefiria Aakusu

Basic Information





January 1

Blood Type



170 cm



Professional Information





Chapter 42


Episode 1

Voice Actors
Japanese Voice

Kikuko Inoue

English Voice

Lydia Mackay

Image Gallery

Sephiria Arks is the commander of the Chronos Numbers and known as Number I.


Sephiria has long, wavy ash blonde hair and pale blue eyes. She has the Roman numeral I tattooed on her forehead, outlined by a lightning bolt on each side. She wears gold shoulder pads reminiscent of a Spanish soldier, and a pink suit jacket with a long, flowing skirt.


In the manga, Sephiria has a very calm, tranquil demeanor. She is one of the most intelligent, skilled fighters yet she never lets her emotions get the best of her. She appears to enjoy Japanese cuisine and culture, as she is seen meditating and carrying on business in a Japanese-style environment several times. She was born and raised to serve Chronos and thus she takes her duties to the organization very seriously. Sephiria often manipulates others into helping Chronos fulfill its goals, especially Train Heartnet. She certainly has a ruthless side to her and has no problem demonstrating it to troublemakers like Creed Diskenth.

In the anime, Sephiria has a more intense, slightly less calm demeanor and is completely focused on serving the needs of Chronos. She has confronted Train several times about deserting Chronos and does occasionally let her feelings lead her in the heat of battle.




Sephiria takes on the burden of eliminating Train after he defects from Chronos. When she meets him though, she offers him several chances to return to the organization. After he refuses, she asks him to return Hades, something he also declines. She eventually realizes that he's completely changed and decides to leave him alone. Before departing from their final fight, she gives him a bullet made out of Orichalcum that would make Hades achieve its full power.

After the rise of the Apostles of the Stars, Sephiria leads Chronos into their stronghold. Sephiria attempts to fight Creed and is soundly beaten in the process. She later watches Train and Creed battle, urging the ex-assassin to use the Orichalcum bullet. However, he manages to stop Creed without killing him, a feat that impresses the Numbers commander.

The bio-weapon Eve is abducted by the Zero Numbers and their leader Mason Ordrosso, all of whom used to be members of the Chronos Numbers. With Chronos itself nearly completely dismantled, the remaining Numbers face a bleak future. Sephiria, Lin Xiao Li, Anubis, Belze Rochefort and Jenos Hazard fight against the Zero Numbers in order to punish them for betraying the organization. At the end of the anime, Sephiria vows to rebuild Chronos to its former greatness.


Sephiria first appears in chapter 42 in volume 5, being commanded by the Chrono Elders to destroy the Apostles of the Stars after the leaders at the world conference are all assassinated. She and Belze Rochefort visit ex-Number Train Heartnet and ask him to capture Creed alive as a sweeper. The commander presents Train with the bounty notice promising 3 billion dollars for Creed's arrest and leaves him to consider her offer.

Keen on utilizing as many resources as possible against the Apostles, Sephiria sends Jenos to recruit Rinslet Walker. She later meets with Rinslet to assess her personality and capabilities. Rinslet is dubious of Sephiria's position as the Numbers' leader and is rather disrespectful at first. After she realizes that she's being put through an evaluation (as well as being mocked by Number I), she attempts to quit. However, Sephiria blithely informs her that she cannot back out of the job and compels Rinslet to work with Cerberus and act as a mole to get inside Creed's base.

After the fiasco that Kranz Maduke and Baldorias S. Fanghini cause in Stock Town, Sephiria asks Jenos to bring Kyoko Kirisaki to her. Apparently Kyoko has turned over a new leaf because of Train and is no longer an Apostle, but the commander wants to be sure the teenager is not deceiving everyone. Using her Christ Saber, she quicky carves a tombstone with Kyoko's name on it and tells her she will be assassinated unless she would like to become a Chronos Eraser. Kyoko refuses because she promised Train she wouldn't kill anymore. Relieved by her answer, Sephiria destroys the tombstone and tells her that she was testing her to see if the promise was actually true.

Later, she goes head to head with Creed and stands a pretty good chance against him. She makes multiple hits that are capable of killing the insane man several times over. Unfortunately since Creed has gained immortality through

Sephiria vs Creed

the power of nanomachines, she cannot defeat him. In a desperate attempt for victory she unleashes her ultimate attack. Creed manages to dodge by forcing his Imagine Blade up to level 3. Her attack took up a large amount of her strength and Creed easily takes her down. Train interrupts the battle as Creed is about to kill her.

Sephiria appears as Train finally defeats Creed and waves off his concerns about her. Apparently her body has been reinforced to withstand significant damage shortly after she was born.

She is seen in final chapter peacefully meditating.

Equipment and Abilities

Sephiria Arks; Sword

Sephiria's sword.

Master Swordsman: In battle, Sephiria wields Christ, a cutlass naval sword made out of Orichalcum. Her swordsmanship is great enough to contend with long range weapons like multiple arrows, machine guns, bazookas and even Hades. She also crossed swords with Creed Diskenth and held her own for a short while, only losing their battle because of Creed being enhanced with both Tao and nanomachines of immortality.

Immense Speed: Sephiria can move so fast that at least three after-images are left behind when she moves.





  • She is the only female member of Chronos.


Main Train Heartnet  |  Sven Vollfied  |  Eve  |  Rinslet Walker
Independent Saya Minatsuki
Sweepers Alliance River Zastory  |  Kevin McDougall  |  Silphy Deacroft  |  Lacdoll  |  Gallom
Elders Willzark
Chronos Numbers Sephiria Arks  |  Belze Rochefort  |  Emilio Lowe  |  Kranz Maduke  |  Nizer Bruckheimer  |  Anubis  |  Jenos Hazard  |  Baldorias S. Fanghini  |  David Papper  |  Ash  |  Lin Xiaoli  |  Beluga J. Heard  |  Mason Ordrosso
Chronos Erasers Clevar
The Apostles of the Star
Main Creed Diskenth  |  Shiki  |  Echidna Parass  |  Kyoko Kirisaki  |  Charden Flamberg  |  Durham Glaster  |  Leon Elliott  |  Maro  |  Doctor
Other Deek Slasky  |  Preta Ghoul  |  Eathes  |  Igor Planter  |  Gyanza Rujike
Other Annette Pierce