The war ends with the good guys winning but a much higher casualty rates leaving wizarding England with next to no men left.
Female harry is a lesbian who plans to use this to her advantage, she has found a spell in the black family library that 'claims' to allow same sex couple to have children. What she doesn't know is that this spell was created by a male head of the black family to punish his lesbian daughter for defying him. The spell actually makes all the women in the area uncontrollably horny and fertile as well as summons the closed living male relative to the caster and when he cums inside the women they are bound to his will.
harry uses it with several witches present, (Maybe fleur and Gabrielle (aged up) delacour, susan bones and daphne greengrass though writer can use whichever girls they choose,) and Dudley gets summoned and goes about breeding the girls with Harry being last and cognisant enough to understand that this has gone wrong but not enough to stop it.
