<p>Except for the fact that he didn’t know about it, couldn’t Harry have made a Horcrux when he destroyed the diary and killed the monster. Do you have to make a Horcrux right away? I would think that destroying a soul would make you able to create a Horcrux because it’s very much like killing except that there’s no body involved. If you could create a Horcrux by destroying one Dumbledore could have created one by destroying the ring Voldemort had used as a Horcrux.</p>