In a universe, Harry Potter finally defeats Voldemort by sacrificing himself but sadly not before that the Dark Lord had killed most of his precious people. In Limbo, he meets various powerful entities that offer him a choice; pass away or go to another dimension and help one of his alternate-self.
If the choice seems simple, there is other factors; if he pass away he has no guarantees to what awaits him; if he goes to this alternate dimension, even if he must continues to battle he he will be guaranteed to find happiness, also he will be permitted and even encouraged to form a harem of witch since there is a shortage of good wizard for the generation of his other-self.
Without to much of thought, Harry chooses to go in the other reality; there, he can do whatever he want, he has only two restrictions: he can help, he can train, he can guide he can even manipulate but he cannot resolve the problems in place of his other-self and he cannot act before that the time is right.
Thus Harry comes in his new world, one month before his 18 birthday and the birthday of his alternate self, quickly he contacts Dumbledore and manages to become the DADA professor, since he is immunized to the curse of Voldemort. After having stabilized his situation, Harry begins to prepare for the following years, after all he has a school full of willing witch to seduce, many past fantasms to realize and as much leeway and permission he can hope.
One of his principal cible, his ownself of this world, Holly Lilly Potter.
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Choose the year when Harry appears, either during Holly First year, in that case, it's Harry who introduce her to the magical world (and begins his seduction), or during Holly Fourth year ("Mad-eye" is relegated to security).
MUST Like Holly (Harry), Neville must also be a girl, and Draco Malfoy must have a little sister or be female himself. (Other can be possible).
