From the publisher:

Collecting three Realm of Kings series in one power-packed hardcover. In Imperial Guard, one hazardous mission may be the solution that everyone is praying for, but are the opinionated and fractured Guard tough enough - and united enough - to accomplish it? And in Inhumans, now led by Queen Medusa, the battered and bruised royal family struggles to maintain their grip on the reigns of power. Courtly intrigues and external threats are beginning to erode their rule, but the biggest threat may lurk within the family itself! Then in Son of Hulk, meet a new monster for a new age, and a challenger to the warring Kings of the Cosmos... he is Hiro-Kala, Son of Hulk, and this young apocalyptic visionary has a destructive destiny: obliterate the Universe! Collects Realm of Kings: Inhumans #1-5, Realm of Kings: Son of Hulk #1-4, and Realm of Kings: Imperial Guard #1-5.