Name: Zagi Nori
Known as:
Dark Zagi
Dark side noa
Unknown hand
Age: Around 28,000 years old
Gender: male
Personality: Oddly, despite his animalistic behavior in Ultra form, Zagi has shown to be rather intelligent, having created a long term plan that actually succeeded and his human disguise showed remarkable skill with hacking and analyzing, being able to even shutdown security.
Appearance:

Human form

Ultra form

Original Abilities:
Dark Ultra Powers: As the creator of the Dark giants Faust and Mephisto, Zagi in theory possess all of their powers. He was stronger than any Ultra shown in the series save Ultraman Noa, being able to withstand all of Nexus' strongest attacks.

Dark Field G Deployment (ダークフィールドG展開 Dāku Fīrudo Jī Tenkai): Zagi can create a special type of Dark Field known as Dark Field G (ダークフィールドG Dāku Fīrudo Jī) to do his bidding. He can use it to create a battlefield, transport Space Beasts or in human form to reflect attacks. He can use it regardless of his state. In the Extra Episode, he used this to enlarge a human-sized Bugbuzun Brood into giant. It appeared again in Ultraman Ginga as the dark vortex from which he appeared.

Self Evolution: According to his past, Zagi was installed with the ability to self evolve, doing so to counter the Space Beast's ability to evolve upon consuming their prey. Unlike other attacks, this one is based on the Space Beast rather than Noa himself.

Mind Powers: As a possible counterpart to a regular Ultra's Ultra Willpower, Zagi has mental abilities of his own like the Visitors who made him, he could erase memories at his leisure as well as use the darkness in people's heart to control them, usually when they are hosting one of his Dark Giants. He can also show people images and illusions like he did to Mizorogi when he gave him back his memories.

Prophecy: Like Noa, Zagi could possible predict future events. For example, he predicted that Nagi would become the fourth Deunamist.
Bullet Freeze: Zagi can freeze incoming projectiles in mid-air by raising his hand before throwing them aside.

Flash Travel: Zagi can encase himself in a large aura of energy to fly to any area he wants as a ball of blue light. This form is also taken once he loses his physical body.

Possession: As a wandering mass of energy, Zagi is able to possess his host and kill their original consciousness for him to take over. When in possession, he is able to mimic original human feats to strengthen the validity of his disguise and maintain his original appearance even after 18 years of possessing the host (which would at least appear as if they were aged).

Extraordinary Jumper: Zagi is able to jump to great heights with ease.

Space Beasts (スペースビースト Supēsu Bīsuto): These monsters, like the dark giants, are Zagi's minions, they are mostly subjugated to his control or be created via his power. When Zagi appeared in person at the end of the series, it caused the Space Beasts all over the world to go active and rampage. After his defeat it appeared that the Space Beasts, while still remaining, were no longer such a threat as before.

Great Durability: Thanks to his Ultra Armor, Zagi is able to endure the finishers delivered by Nexus in any of his forms.

Acceleration: Zagi can move at high speed while surrounded by a dark aura.

Teleportation: Zagi can quickly teleport to any destination he desires.

Copied abilities:
Lightning Zagi (ライトニング・ザギ Raitoningu Zagi): Zagi's basic Ultra Beam. Zagi can emit an extremely powerful beam of dark energy from his vertical left arm, with his right placed on the back of it. This beam rival's Ultraman Noa's in power, but is still not as strong.

Zagi Shoot (ザギ・シュート Zagi Shūto): Zagi can emit extremely powerful blasts of dark energy from his knuckles. These have a huge amount of force behind them and can be fired in rapid succession.

Gravity Zagi (グラビティ・ザギ Gurabiti Zagi): Zagi can launch a stream of lethal super gravity energy by stretching both of his arms forward. There is a charged and an uncharged version of it.

Zagi Reflection (ザギ・リフレクション Zagi Rifurekushon): Zagi can emit a purple barrier that can reflect energy attacks. It is a dark version of the Noa reflection.

Zagi Kick (ザギ・キック Zagi Kikku): A dark version of the Noa Kick, which uses "super gravity" to empower the impact. Although supposed to be a front kick.

Zagi Punch (ザギ・パンチ Zagi Panchi): A dark version of the Noa punch, which induce "super gravity" to empower the blow. Seen used on Jean-nine.

Zagi Inferno (ザギ・インフェルノ Zagi Inferuno): A dark version of the Noa Inferno. Zagi charges his fist with dark flame and punches the opponent.

Zagi Spark (ザギ・スパーク Zagi Supāku): A dark version of the Noa Spark. Zagi created a light blade from the tip of his arm.

Zagi Blizzard (ザギ・ブリザード Zagi Burizādo): A dark version of the Noa Blizzard. Zagi freezes his opponent using a dark snowstorm he summons.

Darkness Zagi (ダークネス・ザギ Dākunesu Zagi): A dark version of the Shining Noa, creating a pulse of darkness and drags the target into his body.

Zagi Wave (ザギ・ウェーブ Zagi Uēbu): A dark version of the Noa Wave which heals only Space Beasts. In Ultraman F, his counterpart used it to heal Dark Faust and Dark Mephisto.

Zagi Galaxy (ザギ・ギャラクシー Zagi Gyarakushī): Zagi's version of the Noa Galaxy, using a dark wave to summon meteorites from asteroid belt.

Zagi Mirage (ザギ・ミラージュ Zagi Mirāju): Creates illusions for his opponent with darkness, based on Noa Mirage.

Zagi Through Eye (ザギ・スルーアイ Zagi Surū Ai): A dark version of the Noa Through Eye, Zagi emits rays of light through his eyes to see in darkness.

Zagi Elbow (ザギ・エルボー Zagi Erubō): Based on Noa Elbow, Zagi performs an ultra high speed elbow strike.

Zagi The Final (ザギ・ザ・ファイナル Zagi Za Fainaru): A dark version of the Noa The Final, it turns all nearby light into darkness, because he lacked the Noa Aegis it is different from its light counterpart and has a different effect.