Post-Flashpoint
In the new 52 he is the eldest son of Trigon, if he remains the father of Etrigan, the father of Merlin, and the father of Scapegoat is unknown.
A cruel and wily demon; Belial is the leader of the three Sons of Trigon. With a flare for arrogance and control he encounters Phantom Stranger in his own home; They later encounter each other once more at Belial’s casino; the Lucky Devil in Las Vegas. With Phantom aided by Deadman in a deadly card game, though the only reason Phantom engages in this risky act is because he thinks that Belial knows where his kidnapped family is being held. Belial loses the game because of Deadman’s interference and swears his revenge for the loss. What adds insult to injury is the fact that Deadman rummages through his mind to see if they know anything about the whereabouts of his family, which enrages not only Belial, but his brothers who swear vengeance for the deeds as well as the fact that Phantom delivered her sister straight to their father. However before all this Belial hints that his sister; Raven might know what happened to his family.
Amongst his Earthly dealings is running of the Lucky Devil casino in Las Vegas, where he employs Lady Luck as one of his dealers. For his own amusement he plays high-stakes poker in one of the back rooms situated on top of a multiversal nexus, which also makes it easy for him to dispose of the remains of those who lose.
It is also of note that his sister loses control of her senses and becomes enraged when she is in proximity of her brothers.
Pre-Flashpoint
Before the New 52, there was no Son of Trigon named Belial. The character has sometimes been confused with Etrigan’s father, of the same name. See Belial.