Caiphon

Caiphon was an Elder Evil from the Far Realm who had taken possession of one of the stars of Realmspace. Unlike normal stars, Caiphon didn't had a fixed place in the sky but instead danced and wavered across the Realmspace.

Description
Caiphon was a purple star.

History
Caiphon, and the other Far Realm-infested stars of Realmspace, were somehow related to the Eldest.

Many believed Caiphon was a guide star, but Caiphon usually betrayed those who relied too much upon it. In times of need, when even prayers to the gods failed, people offered their pleas to the star for help. On rare occasions, Caiphon listened and sent one of its emissaries. The emissary seemed like a good person, trying to help people to solve their problems. But not long after, chaos and war became common in the regions the emissary had appeared.

In 1396 DR, after having lose his pact with the archfey Neifion, the warlock Japheth Donard made a pact with Caiphon.