After Prue’s death

 "After Prue’s death, her spirit did not immediately go into the light. Instead, she appeared in Piper’s dreams—not to say goodbye, but to provide guidance.

In one dream, Piper found herself in high school, with no magic, no memories of Prue. A world where Prue had never existed.

Piper panicked, screaming,

“I need my sister. We could never be Charmed Ones without Prue!”

A voice said,

“You are Charmed One because of yourself. I was the first to awaken it in you.”

Prue stepped out of the darkness, smiled, and then melted into the light.

She never disappeared—she became a part of her siblings’ powerful inner selves."