"Fools! You cannot defeat the will of the Blood God! That which you destroyed was but a small part of the essence of my red master—and by destroying its material form, you have allowed that part of him to return to the heart of Chaos! There are two more relics, each holding another part of his essence, and when the three parts are brought together, Xathrodox the Red Flayer shall return to this world in his full strength, and drink the blood of the weak and the mortal! Blood for the Blood God! Blood…"
- —Deputy High Priest Claus Leibnitz[1e]
While the Ar-Ulric is leading the Knights of the White Wolf in the field, Deputy High Priest Claus Leibnitz is in charge of the temple.[1a]
A Skaven assassin from Clan Eshin is still hiding beneath the city, and it has struck an unholy alliance with a Chaos cult whose members managed to survive without being exposed. The cult, known as the Brotherhood of the Crimson Skull, worships Khorne the Blood God, and its leader is Claus Liebnitz, the Deputy High Priest at the Temple of Ulric. Several other high-ranking followers of Ulric are also involved, although some of them believe they are following a particularly militant sect of Ulric rather than a Chaos God.[1b]
Through his network of contacts at all levels of the city, Liebnitz quickly came to hear about the icon of Sigmar. He has been gathering information for some time with the help of his Skaven agents, hoping to pour fuel on the smouldering theological rivalry between the cults of Ulric and Sigmar.[1b]
As soon as the box was in his possession, he took out the brass skull and hid it in his chambers at the Temple of Ulric, along with various other necessities for a blasphemous ritual of Chaos.[1c]
The box, however, did not stay empty for long. Angered by the sudden appearance of surprise witness (and intended sacrificial victim) Johann Opfer at the trial, Liebnitz ordered his death, which was easily accomplished in the confusion after the trial broke up. When the killers brought Opfer’s head to him, he put it in the chest that had once held the brass skull. This was partly because he needed somewhere to conceal the grisly trophy in his temporary lodgings at the palace, and partly due to his macabre sense of the appropriate—the box was supposed to be holding a skull, after all. It is Opfer’s head, not the brass skull of Chaos, that adventurers will unwittingly take to the Collegium Theologica.[1c]
At the site of his ritual, five Brothers of the Axe stand in a circle around the fire of Ulric; all of them have painted over their Brotherhood insignia with the same red skull design. Within the circle, clad in red and black robes that have nothing to do with the worship of Ulric, stands Deputy High Priest Claus Liebnitz. The brass skull hangs around his neck, with a lurid red light pouring out of its eyes. The hood of his robe is thrown back, revealing a red skull design painted on his face.[1d][1e]
As the chanting continues, Liebnitz draws a large, jagged knife, its hilt set with a ruby carved into the shape of a skull. Slowly, he approaches one member of the chanting circle of cultists, and plunges the dagger into his throat. Blood cascades over Liebnitz as the cultist slowly collapses, soaking the brass skull and causing its eyes to glow with an ever-greater fire. Liebnitz then moves to the next figure in the circle, and the grisly scene is repeated again.[1e]
It should be noted that he no longer has access to any magic—Khorne disdains spells, and having turned to Chaos, Liebnitz has lost all the divine magic of Ulric that he used to wield.[1e]
However, if adventurers take too long to overcome the guards—or if they foolishly wait for the sacrifice to be complete—things take a decided turn for the worse. The light pouring forth from the eyes of the skull begins to coalesce, taking on a hideous shape—that of a Bloodletter, a Daemon of the Blood God. As it begins to solidify, Liebnitz falls to the ground with a strangled scream. Blood pours from his eyes and mouth, and the Daemon takes a moment to lap it up with a long, barbed tongue. The creature becomes fully corporeal. It is a particularly large and powerful-looking example of its kind.[1e]
If the adventurers manage to defeat Liebnitz and his cultists before the ritual is completed, he slumps to the ground in the pool of blood that has been created by the sacrifices and the ensuing battle. The brass skull glows redder than ever, seeming to draw the blood into itself, and the Daemon manifests as if the sacrifice had been completed.[1e]