In Season 6, Warren, a Big Bad wannabe, shot Buffy, and killed Willow's girlfriend, Tara. By doing that, Warren set off a chain of events that led Willow to become Dark Willow, and she went on a warpath of revenge, and killed Warren; then she tried to destroy the whole world, until Xander stopped her.

Considering the fact that Buffy is Willow's best friend, and she was also shot by Warren, I can't help but wonder: If Buffy had died instead of Tara, what would Willow have done? Would she still have become Dark Willow and killed Warren for revenge? Or would Tara have been able to stop her in this new reality?

I know that if Buffy had died, a new Slayer would've taken her place; but what would Willow have done until that new Slayer came forward? What do you think that Willow would've done if Buffy died instead of Tara?

(References: Google Images- HeadHunters Horror House Wiki- Buffy the Vampire Slayer 6x19, Seeing Red)