From the back of the book:
A Gamemaster's biggest challenge can be prep time.
With busy lives in mind, we created a book that has new and exciting content to help save hours of time preparing for a game.
Masters and Minions includes many interesting "Big Bosses" and focuses on how they use their minions.
Masters and Minions provides tips and strategies that you can "drag and drop" into a new or existing game.
Masters and Minions includes new content spanning levels 1—20, so it will continue to provide you new and exciting content as your players level up!
Encounters for PC levels 1-20
Encounters are categorized into levels 1-3, 4-7, 8-10, etc., to add variety to any campaign.
Lore and descriptions on each Master and how they use their Minions.
Every Master has story hooks and strategies on how to be used effectively.
—ALL NEW content—
Strategy tips—New spells—New magic items!
New NPCs and more!