Here is a complete list of all Unicorn Overlord characters, including companions, enemies, seiyuus, classes and their backgrounds.
Unicorn Overlord details more characters, classes, combat systems
Unicorn Overlord characters: Classes, companions, seiyuu
Unicorn Overlord characters: Classes, companions, seiyuu
Unicorn Overlord Characters and Gameplay Detailed - Siliconera
Unicorn Overlord characters: Classes, companions, seiyuu
Unicorn Overlord Reveals New Characters, Class Types - Persona Central
Meet the Unicorn Overlord Characters you'll fight alongside with! - Sakura Index
Unicorn Overlord details ally characters, nations, and exploration - Gematsu
Unicorn Overlord Reveals New Characters, Class Types - Persona Central
Unicorn Overlord - New Character and Gameplay Details
Unicorn Overlord characters: Classes, companions, seiyuu
Unicorn Overlord Unveils New Characters, Classes, and Training Methods - GamerBraves
Unicorn Overlord - New Character and Gameplay Details
Overlord (2012) (Literature) - TV Tropes