Sorcerer's hold a great deal of power in the world of The Witcher, and the sorceress Philippa Eilhart is no exception to this rule. Ambitious and driven, she was Redania's puppet master after King Vizimir II's assassination, a murder she almost certainly orchestrated. With more than three hundred years to perfect her craft, Philippa was one of the few sorcerers able to polymorph, and it was in her owl form that she guided Geralt through the "Eternal Battle" in The Witcher 2: Assassins of Kings.
She was a known associate and lover to Sigismund Dijkstra, with whom she led the Thanedd Coup against the Brotherhood of Sorcerers to reveal traitors working for Nilfgaard. After seizing power, the two of them worked behind the scenes in Redania, a ruling iron fist gripping tight to the reins of power as long as they could hold onto it. Though she did act as Dijkstra's lover for a time, the truth was that she preferred the sexual company of women, and she was only using him to expand her own personal power. She later worked to form the Lodge of Sorceresses and was considered its primary leader until the Witch Hunts, which allegedly saw her torture, execution and martyrdom.
While Philippa didn't appear in CD Projekt Red's first Witcher game, she was mentioned on numerous occasions. There is a strong likelihood that when Geralt awoke to hear Triss speaking with someone in her apartments, Philippa gave her direction. In Assassins of Kings, Philippa played a major role, appearing in Chapter 1, when Geralt spied her through Sile de Tanserville's megascope. She maintained a house in both Vergen and Loc Muinne.
In Vergen, she was counted among Saskia the Virgin of Aedirn's inner-circle, a magical advisor who seemed to be all for Saskia's plans to form a free Aedirn. When Saskia was poisoned, Philippa gave Geralt the list of ingredients required to save her life, but her motivations were hardly altruistic. Unknowing, Geralt provided Philippa with everything she required to charm and manipulate Saskia into doing her bidding, using the Witcher and Iorveth both to carry out her plan.
The player was then presented with an opportunity to either help Philippa escape or save Triss, but regardless of Geralt's choice in the matter, Philippa found herself at King Radovid's mercy. Radovid, whom she had mentored and advised after his father's death (obviously pulling the strings in Redania behind the throne until he came of age,) hated mages because of his time with Philippa. He claimed that she tormented him endlessly, and as punishment for her crimes against him, he plucked out her eyes. Her fate was left up in the air, with many assuming her to be dead after the Witch Hunts.
She wasn't killed, however. Evidence of her resurfaced in The Witcher 3: Wild Hunt, while Geralt was investigating Crookback Bog. He found a doll imbued with black magic by the Crones of the bog, and the feathers adorning it reminded him almost immediately of Philippa Eilhart. The doll was crafted in the likeness of the person the Crones wished to control, and though there was no direct evidence suggesting Philippa was their puppet, the implications didn't sit well with the Witcher.
Concocting a plan to regrow her lost eyes, Philippa went to Novigrad to seek out her former lover, Arthur de Vleester. She thought he could help her with her plan, but when Arthur convinced her to stay in her owl form to remain safe, he sealed her into that form with a dimeterium band around her ankle. Unfortunately, Arthur was killed during the witch hunts, and Philippa was trapped in her owl form. She came into the possession of Zoltan Chivay, who named her Poppy. Zoltan later lost her to Dijkstra, who removed the dimeterium band unthinking and returned her to her human form.
Philippa attacked, but Geralt was able to stop her with an offer of protection from Emperor Emhyr var Emreis in exchange for help against the Wild Hunt. If Geralt chose to participate in Radovid's assassination, Philippa spied on his meeting with Dijkstra, Thaler, Roche and Ves, then later confronted Geralt as he left the meeting. She gave him Vizimer II's ring as proof for Radovid that he had her captive, and when Radovid went to the place where she was waiting, she blinded him with magic dust and then killed him for what he'd done to her.
Later, she helped Geralt search for the sun stone, which they would use to lure out the Wild Hunt, and after locating it, she gave it over to him freely; despite his assumptions, she would keep it for herself. Philippa confessed that she intended to take Yennefer's place in Nilfgaard and become Cirilla's advisor when she took Emhyr's throne.
There is no denying Philippa Eilhart's lust for power above all things. Even her choice to take Yennefer's place as Ciri's magical advisor was a grab for the ultimate power, as Nilfgaard remained the most powerful Empire in history. She was not above manipulation, seduction or even murder to get her hands on what she desired above all else: power.