Charmed What Ifs & Explainations

What if Prue lived & met Paige? What if Piper died instead of Prue? Or Pheobe? How would that affect Paiges Powers?

When Chris goes into the past, he's told about another aunt he never met. the boy is already on the quest to save hia family, could he do it again and save the Charmed Ones from the pain they suffered when their older sister Prue died? Is it worth paying the price to see the eldest Halliwell sister alive again?

What if Pheobe had remained Queen of the Underworld? Would Prue & Piper have the strength to vanquish their sister a 2nd time?