One Darkness
One Darkness Final Desgn
Human Host/Form: {{{Human Host}}}
Gender: Male
Age: 10,000 years old
Height: 49,000 meters
Weight: 37,000 tons
Home world: Land of Darkness(formerly, created place)
Series: Ultraman One
Type: Villain(formerly)
Fighter Type: {{{Fighter Type}}}
Fighter Sub-type: {{{Fighter Sub-type}}}
Family Ultraman One(Template, Ally)
Affiliation Ultraman Belial(Former master)
Ultraman Xena(Brother in arms)
Ultraman Giga(Brother in arms)
Ultraman Cure(By Association)
Created by Zhu Huong

"This fight will come into reality, soon as you see Ultraman One." -quote in episode 5

Ultraman Kato is an Ultra that is an exact template of Ultraman One. Kato is formerly known as One Darkness before he joined the light and defect from Belial's side. As One Darkness, he is cruel and ruthless like Belial. As Ultraman Kato, he is kind and gentle, also awoke the real Kato Mosa and getting a proper merger with him. At the end of the series, he left Kato and when to the galaxy to explore. He returns in Ultraman One: The Continued Chronicle to battle against the Evil Messiahs.

History Edit

As One Darkness
  • Note: As of this part, One Darkness is still has this as his name instead of Ultraman Kato.

Ultraman OneEdit

One Darkness appears to fight against One and overpowers One and defeat him and disappear away.


As Ultraman Kato
  • Note:.As of Episode 17 of Ultraman One, One Darkness is now Ultraman Kato.

Ultraman OneEdit



One Darkness looks similar to Ultraman One without any differences except for his eyes.He looks like Zero Dark but it body design are similar to One.

In One Darkness Calamity,he has additional crimson red markings and more blue colour on his body.

When redeemed,his looks like his normal former dark form except his black and crimson red markings replaced by red and orange colour.

Powers/Forms and Body FeaturesEdit

  • Age:10,000 years old
  • Height:49 meters
  • Weight:37000 tonnes
  • Swimming Speed:350km/h
  • Swimming Depth:4000 meters below the sea.(All forms)
  • Flying Speed:Mach 4
  • Hobbies:Training and defeating One.Insulting others and bullying.
  • Dislikes:Fighting,Ultraman One and other Ultra.
  • Human Host:Kato Mosa
  • Family:
  • Ultraman One(Template, later ally)
  • Ultraman Belial(Creator and Master and later foe)
  • Affilation:

Ultraman Giga,Ultraman Xena

Body FeaturesEdit


One Darkness is seemingly evenly matched One.One Darkness techniques are similar to One.But only displayed the following.One Darkness also has powers that One do not have.



  • One Dark Shot:One Darkness version of the Wide Shot, it is purple in colour and equally matches One and Zero's.
  • Dark Crossium Shot:Dark version of the Crossium Shot, One Darkness charges this ray like how One charges his.His ray is seemingly overpowers One but evenly matched in the end.
  • Dark Cannon:Dark version of the Emerium Cannon.
  • Dark Triple Slash:One Darkness can fire the Dark Version of the Triple slash by putting his three sluggers in his chest.
  • Dark Edge:Arrow-shaped beam, can cause small explosions or damage.Used to take down One who was flying back to his planet.
  • Mind Control:One Darkness can influenced other people's mind by firing a dark ray from his beam lamp.
  • Darkness Ultimate:One Darkness dark version of One's One Final Rainbow light.Creating a pulse of darkness and has a different effect.Used in the 6 episode.


  • Darkness Kick:Like One, One Darkness can also jumps to the air very high and perform a kick with his legs covered with purple minus energy.
  • Darkness Punch:Punch version of the Darkness Kick.One Darkness charges dark energy from his hands and punch at his opponents.


  • Dream Invasion:In human form,Kato Mosa can enter one's mind by transforming into One Darkness.Seen in episode 5.
  • Darkness Field:A dimensional field where One Darkness transform himself and his opponent to a dark dimensional similar to the Land of Darkness.
  • Claws:One Darkness can change his fingers into claws that can cause pain against his foes.However, he loss this ability after he detected to the good side.
    • Darkness Control:One Darkness can forcefully enter the mind of a person and then uses reiyonx energy to control them and uses them as a puppet for various purpose.
    • Reiyonx Control:One Darkness can control a reiyonx by hitting them with Reiyonx energy.This is done through his claws.
    • Darkness Cntrol:One Darkness can inject his claws into his enemies to corrupt them or controlling them in order to create a human host.
    • Ripper:One Darkness can charge his claws with shockwave.

Unseen AbilitiesEdit

  • Darkness Blizard:One Darkness can freeze his enemies by fired a series of ice towards them.


One Darkness upgraded form, to match One's Crescent Form.It has superior strength and speed.It this form, One Darkness has his old powers.In this form,One Darkness do not use his sluggers instead he rely on his claws and his natural abilities.

Powers DemonstratedEdit

  • Calamity Claws:One Darkness Calamity can create Reiyonx claws,but his are longer and dagger and scythe like now.Able to slash painful wounds towards his foes.
    • Corruption:Using the improved claws,One Darkness inject minus energy to their mind to corrupt them.He can even use it on pure kaiju and turn them to his puppet.
    • Razor Claws:One Darkness Calamity can change his claws into razor sharp edges that can cut Ultra Flesh and weaken their energy.
    • Claws Destroy:When cutting Ultra Flesh,the minus energy released will destroy the inner light and stop foes from hitting him.
    • Claws Tether:A dark light from his clwas.
  • Strength/Speed:He has boosted strength,able to easily stagger One's Blaze Form and Crescent Form.He also boosted his speed,able to match One's Agile Form flying speed.
  • Dark Crescent Blow:One Darkness charges his hands and creates a half moon crescent same size as his height and fired at opponent.It will start to swing towards foes.Foes are defeated instantly.Similar to the Ultra Slash.
  • Deathcium Slash:A Attack similar to Zero Darkness's Deathcium Slash,has similar power.
    • Giga Deathcium Slash: A gigantic version of the Deathcium Slash.
  • Calamity Deathcium Shot:A improved version of his Dark One Cross Shot.He gathers all his minus and Reiyonx energies and fires as 'L' style,his most powerful Attack,It is more powerful than One Cross Shot but weaken then One Pure Ray.
  • Power Absorb:Something his original never have,he can absorb other beings energy to power himself.
  • Dark Bang:A energy punch,covered his hand with dark flames.
  • Enchaned Emerium Cannon:A more powerful version of his Emerium cannon.
  • :Eyes Beam:A beam from his eyes.
  • Dark Dynamite:One Darkness Calamity can cover himself with dark aura and release it from his entire body.An explosion enough to destroy a small moon and destroying anything on his path.He used it thought can destroy One but One defended from the Ligtning Spark energies.
  • Darkness Blizzard:Same like his blizzard,he can fire a blizzard to freeze foes.
  • Dark Fire:He can fire a darkness fire from his hands.

Light form

After being freed from the darkness that held him and Kato Mosa, he seemly turned into light and his dark powers become light. In this form, his eyes glowed yellow and has a blue color timer and his claw are back to normal hands. He is now fully empowered by the Lught of Purity and not Light of evil.

Powers and AbilitiesEdit

Most of his powers are retained in his dark forms but are lighter versions of his original powers but has the addition of new powers. Special Moves

  • Specium Ray:Yellow version of the Specium Ray in L style.
  • Specium Slicer:Energy slicer blades, can cut through any material.
  • Specium Light Ring: Light version of Deathcium Slash.
    • Giga Specium Light Ring: Kato can fire a larger version of the Specium Light Ring. Used to cut through Hell-Death pincers.
  • Specium Dynamite: Kato engulf himself in specium energies and concentrated it in a blue aura around his body and rushes towards foes.


  • Light Punch:A punch attack.
  • Thick Hide: One Darkness/Kato has a thick hide/armour around his body, is shown that One Darkness when hitted by Belial's deadliest powers, as Kato, he only receives lesser injuries that a typical Ultra Hosts.
  • Light Kick:A kick attack.


  • Sluggers:Crest weapons from his head,can be used in combat.
    • Sluggers Attack:A slash attack.
    • Sluggers Shot:When attached in his head,One Darkness can fire a powerful Ray from his sluggers in his head.
    • Slugger Blade: Kato can change his sluggers to a deadly blade.


  • Light Shield:A light shield erected from his both hands.It represents a pool of light energies.
  • Light Blizzard:Brought over from his dark forms, Kato can create a blizzard to fire foes.
  • Energy Restore:A light Ray that can restore other allie or monsters.
    • Light Unleashing:One Darkness unleashes all his light energies to revive or heal others.Used to revive Zero and heal his friend after losing to Belial.
  • Interdimensional Travel: One Darkness/Kato can travel across various dimensionals across the multiverse.
  • Lifeforce Return:Used to seperate Kato Mosa from One Darkness. It also restores their life force.


  • Ultraman Kato is also another Ultra redeemed from the darkness but he is the first Ultra to rename himself as an 'Ultraman' instead of retaining One Darkness as his original name.