Belial is a Creator of potentially Void origin. Their essence leaves trail of Void magic, which means that they were likely made in The Void, but there is no way to verify as the dimension and Belial are too dangerous to approach.
As a result of their magic, Belial and their Creations are immune to The Void's control. Their powers are that of an average Creator but they are incredibly dangerous due to the risk of Void spread.
Belial, Behemoth and their Creations share the curse, the cause is unknown. Further information related to their curse has been classified by Pure Creators, therefore I will not disclose it for the safety of Belial and their Creations.

Belial is a childish Creator, not taking anything too seriously unless it's related to Behemoth, CODENAME-000 or their Creations. They usually find ways to goof around with the Creations and try to make them happy through what they deem comedic.
Belial is rather skittish towards strangers, and is afraid of sudden movements coming from people they don't know about. Despite their thousand-year age, they act the same way they did when they were born, it is likely that something prevented their mental age from progressing, so the same thing happened to their body as a result.
When it comes to Behemoth and their Creations, they're frighteningly protective, going as far as to try to terminate whoever they deem a threat on sight, however, they're terrified of CODENAME-000 and won't attack it despite the threat it poses.

Belial has a relatively underdeveloped body, similar to that of a young Creation from their world. They sport plantigrade legs and two arms. Belial's color scheme is mostly gray, with the exception of their dark green mane and stripes.
Their limbs are segmented in 3 parts (upper, lower and hand/foot). Their chest is separated from the rest of their torso, being of a darker shade of gray while also having two triangular white markings on each side at the bottom of their chest. At the lower part of their torso, they have two sharp, white stripes that stem from their back and end after a short distance at the front of their body. Their arms and legs are fully gray.
Their face is actually a gray mask with three horns on each side. Despite their appearance, the horns are actually flat. Belial has a boxy, but rounded snout with a horn at the outer edge of it. The upper jaw has two gray fangs that are part of the snout and aren't actually teeth. Their lower jaw is grayer than the rest of their face, similar to their chest, and bears no teeth or a tongue, the inside being pitch dark. Belial has six eyes, three on each side. Two, bigger eyes are permanently open while the other, smaller ones are closed most of the time. Their sclera is a faintly glowing light purple while their pupil is pitch black.
They have a long tail with a sharp end. The base of the tail has two white stripes, similar to their lower torso, while the latter part of the middle has dark green feathers that grow larger towards the end.

Belial can create a liquid substance using their magic, which can be solidified into objects. The danger this liquid possesses is great because of its magic type. They are capable of regeneration faster than that of an average Creator. Their unique power is being able to grow pitch black tendrils out of their mane. While these tendrils have incredible offensive ability, they seem to be a part of Belial's body, and not something they create as a weapon or tool. The tendrils are as resistant as Belial is, however, they are of a fixed length. It is assumed that these tendrils are what Belial uses to regenerate, as they permanently keep the unused ones in their mane, their role being both that of limbs and regeneration.