From the PDF introduction
A Short Adventure for Four 17th-Level Player Characters Featuring Material from Champions of Ruin
Champions of Ruin addresses the evil campaign, both as a general concept and as it applies to games set in the Forgotten Realms Campaign Setting. The book also offers invaluable tips for running evil PCs as well as overcoming evil NPCs.
Vanrakdoom is a short D&D adventure for four 17th-level player characters (PCs) that utilizes the new material in Champions of Ruin. It takes place in Wterdeep, also known as the City of Splendors, which lies on the continent of Faerûn in the Forgotten Relams Campaign Setting. Famed for the legendary dungeon called Undermountain that lies beneath its streets, Waterdeep draws adventurers from all over Faerûn. Dug by the shield dwarves of Clan Melairkyn and their successors, Undermountain consists of nine major levels and fourteen sublevels. Halaster, the Mad Mage (detailed on page 180 of the Forgotten Realms Campaign Setting and updated on page 294 of the Epic Level Handbook), rules this sprawling complex. However, many powerful creatures have carved out personal demesnes within the sprawling caverns and chambers of Halaster’s Halls, and the Mad Mage of Undermountain has largely ignored their presence.
A confused tangle of sublevels between levels 4 and 6 of the main dungeon has come to be known as the Dark Levels of Undermountain. Since many of these sublevels are accessible only via portals, few have been explored by outsiders. Several of the Dark Levels, all ruled by undead creatures, are collectively known as dooms.
One of these sublevels, known as Vanrakdoom, is controlled by the Church of Shar. Penetration of this area is a mission appropriate for a group of four 17th-level nonevil characters. The inclusion of a cleric in a party planning an excursion to this area is highly recommended.
As always, feel free to adapt the material presented here as you see fit to make it work with your campaign.