Belial is the 68th demonic spirit in the Ars Goetia, and one of the four crowned princes of Hell ruling over the North.

Belial is a mighty and powerful king as he was created right next after Lucifer and is of his order. He appears in the form of a beautiful angel sitting in a chariot of fire and speaks with a comely voice. His office is to distribute preferment of senatorships and to cause favor of friends or foes. He was the demon that indirectly created the Vampire Nosferatu known as Count Orlox. He is also the father of the demon princess Fierna. Belial is the demon of lies and guilt and is able to induce to any type of sins, especially those related to sex and lust.

After the fall of the Angels he was against God and Heaven, though likely this was due to sloth. He would eventually decide to continue to be apart of Stygian Council and became a King of Hell. Belial is the partner of the demonic Necromancer Nebiros and the uncle figure of the spirit of Alice Liddell.

He bestows excellent familiars and governs 80 legions of spirits. Whoever summons him must have offerings of gifts or sacrifices or he will not give true answers to their demands, but even then with will not spend more than one hour on the truth unless constrained by divine power or his seal, to be worn as a lamin by the person who summons him. He is a profane being, reveling in the pleasures and pains of the flesh. He resides in the city of Abriymoch in a palace of jagged obsidian built on one lip of the caldera. Being of Lucifer's order when he was an angel and later becoming a high-ranked demon of Hell, Belial is a monstrously powerful demon. In the distant past, Belial posed a large threat to even Mundus himself and his reign as a whole, which made Trish believe that Belial could have more than likely defeated Mundus even when the Dark Emperor was at his prime. As an angel, particularly of the Cherubim order, Belial was able to slay numerous angels during the war in Heaven and as a demon, slaughtered large demonic armies that attempted to move against him or any of the other seven great kings. He was even capable of fighting Sparda, who was also in his prime, for a long period of time before being defeated by the Dark Knight.

After his subsequent release from Treachery, Belial's power and strength had not weakened nor was it hampered in any way as he remains just as powerful as he always was even after being imprisoned within Cocytus for thousands of years. His emergence from Hell to Earth created a tremor that was felt by supernatural psychics from miles away, and his first display of power was destroying New Mexico in a burst of Hellfire by simply flicking his index and ring finger upwards. He was capable of holding his own against multiple werewolves simultaneously, before effortlessly besting them, as well as defeating a Nero who had awakened his full Devil Trigger. Belial could even fight near evenly with Dante and Vergil, who both awakened their full demonic power.

Despite his tremendous skill with demonic energy and Hellfire manipulation, Belial prefers to engage via physical combat. He was fast and strong enough to be able to surprise and effortlessly kick Dante through a wall and clear out of the street with a single kick. He was also more than skilled enough with his Stygian Staff to hold his own against both Nero, Vergil, and Trish. When in Devil Trigger, Belial's physical and demonic prowess skyrocketed. He was able to effortlessly defeat a wolf pack, and Hellboy in a single blow each and was even able to quickly out-maneuver Dante in a sword fight. Using his bare hands, weapons, and powers he was able to contend against Dante and Vergil in their enhanced Devil Triggers as well as wielding his sword to their full effect. However, it was not until that the Sons of Sparda assumed their Sin Devil Triggers that Belial found himself significantly overwhelmed.