From the publisher:
Villains: Rebirth is the electronic reprint of our popular Villains product. It contains all of the material from the original work, plus all of the bonus materials included in e-Villains. This new combined version contains 24 villains suitable for placement into any fantasy world, an assortment of villainous spells ideal for surprising stalwart bands of heroes, magic items that no true villain should be without, four new prestige classes, and the outsider known as the ahazu. Challenge Ratings range from 1 to 25, and each villain contains notes about how to bring them into a low- mid- and high-level campaign.