Agrael's Trial in Heroes 5

The Demon Sovereign has lost his aide on the earth, a reliable eavesdropper and a loyal executor, who has been administering his will in the surface world implicitly. The job of honor is vacant now, and Kha-Beleth is going to fill it as soon as possible. Which of the ambitious Demon Lords will be found worthy of the great honor and become the Dark Sovereign’s right hand man?