A stunning 3D portrait rendering of a ghoul sentinel standing watch at the infernal gates of the underworld. Its skeletal structure is draped in tattered, ancient rags that flutter in the searing winds. Piercing, incandescent red eyes burn with a malevolent glow above a grim, lipless mouth set within a smoldering skull. The ghoul's elongated form towers ominously, each bone intricately detailed, offering a chilling testament to its eternal vigilance. Behind, a hellscape of roaring flames and crackling fire casts a menacing glow, illuminating the creature with dramatic red and orange hues. The ambiance is dark fantasy horror embodied, with an artstation level of exquisite detail and soft-focus background. The lighting is cinematic in its intensity, capturing the terrifying beauty of this infernal guardian.