Seer

A Seer is a magical being who can foresee the future. Unlike Oracles, they can see into the future without the help of crystal balls, although they are sometimes used.

There were three demonic Seers that have appeared in the course of the series.
 * The Seer - Known specifically and likely exclusively by title, this Seer served The Source of All Evil for hundreds of years. She was an upper-level demon.
 * The Crone - This Seer is a well respected Seer and advisor to powerful evil demons. She was an upper-level demon.
 * Kyra - This Seer had information on the Avatars and wanted to become mortal. She was a low-level demon.

All these Seers had varying degrees of adherence to evil methods. The titular Seer was purely in allegiance to power, the Crone was generally evil but seemed more interested in preserving demon-kind than empowering herself, and Kyra was essentially a good person trapped in her demonic upbringing. (A glimpse of how these three would get along interacting with each other can be seen in the very similar dynamic shared by the three brothers of the Rowe Coven). All three also were referenced as being centuries old, and all three were also finally vanquished over their course on the show - the titular Seer and the Crone by the Charmed Ones, and Kyra by Zankou.