Íseldur

Íseldur looks like Big Chill's Ultimate Alien Force design. He shares the same colour palette as Ice Moth, although slightly altered. His hood is always seen covering his left eye, and he is always seen in his cloaked form. He has grey eyes.
Underneath his cloak, Íseldur wears a grey and silver Plumber Suit, although it is barely visible.

In Kylmyys, Íseldur was very wise and calm, willing to reason with his natural predators after being exiled for overthrowing the Necrofriggian government. He was a bit rebellious against the Necrofriggian government, but was able to find inner peace despite his siblings being eaten by said natural predators during his exile.

On Earth, and in Plumber Headquarters, Íseldur is socially awkward and is relatively lazy; always seen slacking or falling asleep on the job. He usually tends to get distracted and always complains that he is tired. Íseldur is either too emotional due to stress, or emotionally drained from being too tired. He is always seen slumped over.

Íseldur loves sleep.

Íseldur is autistic, and usually talks about his hyperfixations to his friend, Mimetite. He was also the one who gave Mimetite the nickname "Rocky". He also loves writing stories in relation to his hyperfixations.

Íseldur was hatched in Kylmyys along with his six other siblings during a crisis between the Necrofriggians and their predators in a mass extinction event. Unlike his siblings, with all of them eaten by the Psycholeopterrans, Íseldur was the sole survivor.

When he was thirteen, Íseldur overthrew the Necrofriggian government and was exiled into the territory of his predators. Fortunately, he was able to make a peace treaty with them and found inner peace.

Íseldur was accepted into being a Plumber due to his ways of managing to form a treaty for both Necrofriggians and Psycholeopterrans to co-exist. At the same time, he met Mimetite, and the two of them have been friends ever since.

Being a Necrofriggian, Íseldur shares the same powers as his species, including:
Cryokinesis
Ice Constructs
Freezing Breath
Wind Breath
Freeze Rays
Cryokinetic Touch
Intangibility
Cryo-Phasing
Flight
Levitation
Sharp Claws
Foldable Wings
Enhanced Strength
Enhanced Durability
Enhanced Speed (via Flight)
Enhanced Reflexes
Enhanced Stomach Capacity
Stomach Heat Insulation
Space Survivability
Underwater Survivability
Radiation Immunity
Cold Immunity
Heat Resistance
Prehensile Feet
Strong Teeth
Snow Generation
Ice Shard Spit
Mouth Expansion
Solid Matter Ingestion
Liquid Ingestion

Íseldur has hold of his own Plumber Badge.

The Nega Verse is the timeline of Nega Ben from Ben 10: Omniverse.