Grelik is a leader for a villainous faction that can slot into any fantasy world, but he was originally used in a GLOG oneshot where the players had to rescue their hometown from his cult, which was attempting to summon a Grelugon in the town square.

Grelik the Opalescent is a wicked duke of Hell - a devil whose domain is scarabs, evil beetlelings, and accumulated refuse. He wheels the moon-sized Orb of Abhorrence through the vaulted skies of Hell in an endless quest to capture all the forsaken impurities of existence into one abominable home.

His own personage appears luminous, like an insectoid angel, and he ripples with waves of enchanting color that starkly contrast the vile and haphazard sphere of refuse that is both his most powerful artifact, his punishment, and the symbol of his cult. Grelik revels in this contrast, viewing himself as pure and perfect, while the orb (in his mind) demonstrates the purity all around him. But while his carapace shines like a rainbow star, his heart within him is full of all the uncleanness that the orb manifests externally.

Though he strongly prefers to be left to his endless accumulation of new filth for the Orb of Abhorrence, he is quite deadly if forced to fight. He wields the orb itself in battle, attempting to crush foes under its colossal weight. For those caught in the Orb, death is the superior outcome. Those who survive are melded to the Orb's substance, after which only the death of Grelik can free them from their torment.

Grelik's first weapon is his cult. The underground-dwelling cult of Grelik is almost exclusively composed of wicked beetlefolk who crusade endlessly for a parody of purity, led into battle by Grelik's fearsome Shining Blackguards, beetlelings who don heavy armor enchanted to glow in radiant colors in imitation of the appearance of their master. The cult is fond of wearing heavy armor, training Gem Shrikes as attack dogs (Gem Shrikes are wicked beetle-like monsters with long legs and impaling horns), and employing the horrifying battering rams/burrowing engines known only as the Unholy Symbols of Grelik. These symbols are the cult's most legendary weapon - giant spheres of metal and filth that can dig through the earth or surface defenses with equal ease, paving the way for the cult's conquests.

The cult also employs Grelik's favored servants, the Grelugons. These devils are miniature versions of Grelik himself, and wield wicked chakrams taller than a man to devastating effect. As their name suggests, they are offshoots of the more widely known Gelugons - Hell's icy enforcers. They have lost their icy association for greater strength and a more well-rounded defense against the elements. These directly communicate Grelik's will to the cult's upper echelons.

Grelik's will is simple, though the plots of the Grelugons to accomplish it may be quite subtle. Reveal wickedness in others (but never the cult) and accuse and destroy the humble and simple folk of the world. Between these two tasks, the cult has kept busy and battle-trained for as long as it has existed. The cult has needed that toughening, as the nobler factions of the underdark realms have opposed them strongly, smashing cult strongholds wherever they find them. Though militaristic, the cult is no match for the organized wrath of the Dwarven Kingdoms or the stealthy vengeance of the Deepways Rangers. As such, they are never found in one home for long, and the grumbling of the Unholy Symbols of Grelik never truly comes to an end. Though it wearies the cult, it secretly pleases Grelik, who himself could not escape his sisyphean relationship with the Orb of Abhorrence if he tried. So both cult and master wheel endlessly through the darkness, the shining of their armor hidden in the filth ahead and concealing still more filth within.