BATTLE OF SUNNYDALE. Buffyverse Term/Concept/Idea/Intratext.
The final, climatic clash in "Chosen" between the übervamp army of The First and Buffy, Faith, Spike, Giles, Willow, Dawn, Xander, Andrew, Robin Wood, and the SITs.
At the outset of the battle, Willow's magic uses the scythe given to Buffy by The Guardians to the power of the Slayer to all Potentials in the world, including the SITs--"some thirty-odd pimply-faced girls" who "don’t know the pointy end of a stake," as The First/Caleb caustically describes them. Now empowered, they help Buffy and the Scooby Gang beat back the übervamp onslaught until the amulet worn by Spike destroys the Hellmouth, killing Spike and creating a giant crater into which Sunnydale itself topples.
Casualties of The Battle of Sunnydale include Anya, Amanda, and, of course, Spike.