We really do need more chapters. Buffy sodomising Willow, Faith taking a turn on Dawn when Buffy wasn't there to save her, ect. Maybe add Tara to this story as well.
Really most get some new chapters. Maybe have Faith butt fuck Dawn, or the place's magic messes with Buffy's head and together with Faith they spit roast Willow. Stuff like that.
It would be nice to have a sequel with Buffy fucking Willow's asshole.
Excellently written. Interesting - could see this 'what if' going all sorts of fun ways.
Chapter 3: I'm enjoying this story a lot, even more so than the original version.
This version seems more focussed and more realistic as well, with Faith domming Willow and Buffy treating Dawn a bit better.
Also liked the little cliffhangers at the end (Willow publicly presenting her thoroughly fucked ass/Faith walking on on Buffy buggering her kid sister).
Keep up the good work.
This new concept of telling short segments of story might help with the way original Gehanna story seemed to lose focus from time to time.
You might also want to cut down a bit on all of the screaming aloud of "Fuck me!", "Fuck my bitch ass!" etc. Instead how about getting the reader more into the head of the characters involved and give use a good sense of what the characters are feeling, how the acts they are preforming or experiencing excites them, and in the process excites the reader as well.
You did a good job of getting into the heads of Faith, Cordelia, and Buffy in "Wanting B, Taking C, Having Both". Just don't make mirror duplicates of everything for each character; flow back and forth from one to the other and decide which characters view point is most important at any given moment if you are going to do a third person omnipresent view point.
Now as for the concept of What-If tales set in the Gehanna universe, I have some ideas that might help spark your creativity.
One is to do a tale set a little earlier in season 6 and have Tara in the story or set it a bit later in season 7 and you have the Potential Slayers, Amanda, Annabelle, Caridad, Chao-ahn, Chloe, Colleen, Dianne, Eve, Kennedy, Molly, Rona, Shannon, and Vi available to have shenanigans with.
A few ideas that have also occurred to me are what-ifs based on alternate outcomes to events in various chapters of the original Gehanna story.
For example in chapter 9 when Marti Perkins and Savannah Monroe are introduced what if Amy, instead of playing with herself and watching Marti take Savannah's anal virginity, had equipped herself with another strap-on dildo and taken Marti by surprise in the butt at the same time that Marti was in Savannah's ass. Also the cheerleaders from Glee appear in this chapter but are never wind up involved in any sexual activities.
Or in chapter 20 when Willow is outing Faith as her bitch and Cordelia and Harmony fuck Faith without permission there is a conflict that Cordelia talks her way out of. What if Willow publicly forced Cordelia into becoming Harmony bitch instead?
Another idea is from Chapters 22 & 23 when Willow and Faith are dragged from their cell by the guards. What if instead of Willow being offered a deal by Amy Madison, Willow is deemed too dangerous as a top and Willow is locked into a bondage frame equipped with an anal fucking machine and forced to orgasm from it until she is utterly submissive?
How about some interesting bondage devices related to the Receiving Anal Sex=Submission equation like a magic chastity belt with a built in magic anal simulator?
Finally some characters that I do not remember seeing that I think might be interesting to see in either Gehanna or Amydale.
Veronica & Mac from Veronica Mars.
Elena, Bonnie, and Caroline from The Vampire Diaries.
Jen Lindley & Joey Potter from Dawson's Creek.
Liz Parker, Isabel Evans, Maria DeLuca, & Tess Harding from Roswell.
Chloe Sullivan & Lana Lang from Smallville.
Xena & Gabrielle from Xena: Warrior Princess.
Rose, Martha, & Clara, from Doctor Who.
Wade Wells & Maggie Beckett from Sliders.
Hope my comments help revive your creativity.