8 Mind-Blowing Revelations Hidden In Rise Of Skywalker

Leia's final act is not just connected directly to the mysterious resurrection power of Darth Plagueis but it's only one half of the puzzle. In the climax of the film, Palpatine exhibits the other half and when combined the two abilities show exactly how the resurrection powers mastered by the long dead Sith lord worked.

While Leia may have only used part of this skill the details of how this Dark Side resurrection power would have worked are revealed completely in the course of the film. Like the dyad in the force the knowledge of Force resurrection has been split into two halves.

One half is possessed by General Leia. By having a focus and exchanging one's own life the dead can be brought back briefly. We see this with Han's reappearance, but to bring them back for a sustained period would require more power and for one unwilling to sacrifice his own life there is only one possible solution.

In short, Emperor Palpatine’s Force-vampirism is the second key to resurrecting the dead.

Knowing this, it becomes clear that Darth Plagueis made use of human sacrifices to bring his loved ones back. He would use the same technique that Palpatine uses as he drains Rey and Ben to revitalize himself but at the same time he'd be using the technique which Leia uses, pouring the stolen energy into his focus and bringing back his loved ones at the cost of one or possibly multiple lives.

That JJ quotes from the story of Darth Plagueis at the beginning of the film shows how much he was thinking about this subject when he wrote the screenplay. It seems clear that these two Force abilities are actually two halves of a terrible whole.