Fiber is one of the Shitenno, the Four Heavenly Kings, created by Neos Gold to execute her invasion plans. A combat android possessing free will, Fiber remains unwaveringly loyal to her creator. She has brown hair and wields formidable capabilities, including faster-than-light flight, survival in the vacuum of space, and teleportation. Fiber directly participated in generating the energy pyramid that raised Neos Gold's fortress, Nova, from beneath the Moon's surface.

In battle, Fiber attacks using wires extending from her hands to ensnare or strike opponents. She employs necklace mirrors to project holographic duplicates for distraction or tactical advantage and fires yellow energy beams from her palms. Fiber commands cyclops android minions called Dolls, deploying them during assaults like the raid on the lunar base housing Nagisa Kasumi and Kawai Shizuka; these Doll units attack primarily with sharp claws.

Fiber operates alongside fellow Shitenno Insect, Bigro, and Golem under Neos Gold's command to subjugate Earth.