P. Russell
From Charmed
P. Russell (July 2, 1900 - February 17, 1924) was a witch of the Warren line with the power of pyrokinesis that was turned evil by her lover Anton, a warlock, and killed by her cousins P. Baxter and P. Bowen. She is one of the past lives of Phoebe Halliwell. ("Pardon My Past")
She may have been the daughter of Brianna Warren, niece of Philippa Warren and Lola Mack. It is possible that her father was also magical as her pyrokinesis is not a Warren power and all of her other relatives, except P.Bowen, have a Warren power. Her skills as a fortune teller means that Russell may have had some form of Precognition but not the power of Premonition, since Cassandra Warren was the last Warren witch to have that specific power until Phoebe Halliwell.
It has also been suggested that her first name was Pearl, referring to the couch found in the manor belonging to Aunt Pearl. P. Russell is the only logical aunt, as P. Bowen was most likely the aunt Phoebe was named for (as Penelope Halliwell has no sisters), Patricia Halliwell also had no sisters to have left the couch behind, and P. Baxter was in fact the Charmed One's Great Grandmother.
