So an inflation+pregnancy (whatever that is) path to expansion of the lovely gorgon eh? Well a good story (regardless of how twisted it might be) needs to start somewhere right? So what should be the time period will our favorite lilac-hair Servant with a blindfold find herself on the "bigger" side?
During the Holy Grail War? Or after it?
Oh a bit of forewarning, it the story is going to take place after the Holy Grail War then it has to be after the Heaven's Feel (Sakura's) route because the other two Rider gets a nasty case of dead.