Rivalen Tanthul

Rivalen Tanthul was the first of the twelve Princes of Shade. Rivalen was an accomplished wizard but also The Nightseer, a high priest of Shar, the goddess of loss and night. This made him what the Netheril call a Theurge, blending the magic of the Art and the Power.

Possessions
Prince Rivalen's personal sigil was the symbol of Shar; below it was a pair of curving dark purple ram's horns, outlined in black on a dark gray field.

Activities
Although High Prince Telamont is the temporal ruler of the Shadovars, Prince Rivalen was their spiritual leader. From the enormous Hall of Shadow located near the royal palace, the prince administered Shar's clergy and pronounced her will to the faithful.

Hadrhune
Rivalen was Hadrhune's greatest rival. He resented the approval that his father had shown to Hadrhune, and was secretly working to undermine him. He knew he must exercise great caution, because Hadrhune's enemies had an unsettling tendency of disappearing.

History
In 1372 DR, Rivalen Tanthul's divinations enabled his father, Telamont Tanthul, to finally guide the city back to Faerûn.

Rivalen in The Twilight War trilogy
Rivalen orchestrated, with the help of his brother Brennus, the takeover of the land of Sembia and its reduction to a vassal state of the City of Shade. Rivalen Tanthul then became a demigod/exarch, having absorbed a shard of Mask's power after helping Erevis Cale and Drasek Riven kill Kesson Rel. However, in The Godborn, he was stripped of his divinity when Mask's plans came to fruition, and later died in the ruins of Ordulin along with Brennus.