Slayer power spell

"You shared what made you special with all the Potential Slayers. That power's grown in them. I can reverse the spell. Put it back in you. The power of thousands of Slayers."

- Willow Rosenberg

This spell was a reversal of the Slayer Activation spell performed by Willow Rosenberg, concentrating the power of all currently active Slayers into a single person.

Pandora Project
To defeat the Pandora Project’s leader, Joanna Wise, who had turned herself into a magic-infused cyborg much stronger than a Slayer, Buffy performed with Willow a reverse spell of the activation of the Potential Slayers they had done in 2003. Willow explained that Buffy had shared what made her special with all Potentials, and the power had grown in each of them. Using the Scythe once again, Willow was able to put the grown powers of thousands of Slayers back in Buffy, giving her the ability to even cut magic with its blade and resist an attack of Rain of Death. After defeating Wise and eventually healing herself, Buffy and Willow used the Scythe to return all the power back.

The Reckoning


The next year, during the Reckoning, Willow and Buffy tried to cast the spell again to gain an edge over Harth Fray's demon army. However, Harth, using a staff belonging to one of the Shadow Men, intercepted the spell and, interlocking it into the Scythe, took the power for himself. However, the Slayer connection was too much for the vampire to handle, and he was killed in this moment of vulnerability. His death allowed the power to flow from him back to its owners, and this new Reckoning changed the future into the collective Slayer line continuing up to the 23rd century.

Appearances

 * Revelations
 * The Reckoning