From publisher blurb:
Continuing our Feywild/Shadowfell adventures this month, we have another Campaign Villain complete with schemes, minions, and adventure hooks! The orc warlock Gol'Og, Heir of Shadow, is ready to be the BBEG of your Tier 1 campaign along with his vicious Shadowclaw clan! Included with the full breakdown of Gol'Og and the Shadowclaw clan is the 5th-level adventure Gol'Og's Throne, the penultimate adventure for your characters to face off against the villain!
The Heir of Shadow
Gol'Og, Heir of Shadow, is a Fifth Edition villain designed to serve as a campaign-level threat for 1st- to 5th-level characters. After Gol'Og, an orc shaman found his prayers for power answered by an entity from the Plane of Shadow, he must balance his own ambitions against those of the spirit that now lives in his head.
In this document, GMs will find information that details Gol'Og's backstory, his lieutenants, his goals, and the resources and means he has available to pursue those goals. This document also includes Gol'Og's Throne, an adventure optimized for 5th-level characters where adventurers can confront Gol'Og directly in his lair within the Plane of Shadow. GMs can use this document to craft a whole Tier 1 campaign arc centered around Gol'Og and his cult of loyal followers, or simply take bits and pieces to create a shorter side quest or single-session adventure. Gol'Og and his cult can be placed in any campaign world that features orcs and a Plane of Shadow or a similar alternative.
Gol'Og's Throne
Gol'Og's Throne is a Fifth Edition adventure designed for three to six characters of 5th to 6th level and is optimized for a party of four 5th-level characters. The orc warlock Gol'Og and his Shadowclaw clan followers threaten to overlap the Plane of Shadow with the Material Plane. It will be up to a brave group of adventurers to travel through the shadow gate and defeat Gol'Og and his forces within his Plane of Shadow fortress. Should the adventurers fail, Gol'Og threatens to bring death and darkness through the shadow gate and into the Material Plane. This adventure can be placed into any campaign that includes multiple planes or dimensions, preferably including a plane of shadow, death, darkness, or similar.