|Game||Tales of Vesperia|
|Occupation|| •Duce of Nordopolica|
•Leader of Palestralle
Belius (ベリウス Beriusu?) is the Duce of Nordopolica, who only sees visitors on the night of the new moon. She is the leader of the Palestralle guild, and Natz is her representative. She is also an Entelexeia, an intelligent and long-lived race.
Belius is the sister of Phaeroh. The party visits her to deliver a message from Don Whitehorse and further understand Estelle and her powers as a "Child of the Full Moon". Through her, they discover that she was one of those who built Nordopolica and had also fought in the Great War with the Don's aid. In the middle of their conversation, the Hunting Blades attack Nordopolica, and Belius pleads the party to assist Natz as she fends off Clint and Tison. Once in the arena, they discover that the Hunting Blades have attacked Nordopolica under orders from the Guild Union because of information that the Duce was taken hostage by a monster.
After they save Natz, Belius falls into the arena, wounded. When Estelle tries to heal Belius, her power causes Belius to become unstable, and the party is forced to subdue her. Dying, she forgives Estelle, as her first thought was to use her power to save Belius. She tells Estelle to never lose her compassion and directs her to Phaeroh for more information. Telling Natz to not hold a grudge against Estelle and the party, she dies and turns into the "cyano ciel crystal", which she entrusts the party to give to the Don. When Rita Mordio attempts to use the "cyano ciel crystal" as the basis of a formula to reconstitute aer into mana, she accidentally gives life to what remained of Belius's consciousness inside of the crystal as the Spirit Undine, with the power over the world's waters.
Belius primarily strikes using her body. She can attack in a wide circle using her tail and use the antennae on her head to strike opponents. As she weakens, Belius begins to use her antenna to fire cutting gales of wind. She has one arte: Absolute Freeze (絶対零度 Zettai Reido?, "Absolute Zero"), which summons a jagged mountain of ice beneath the enemy. She also possesses the ability to duplicate herself and attack in both forms.