Harry Potter and the Tuath Dé

All spells, enchantments, and curses have a point where they can be twisted, perverted, broken, or just plain co-opted. This is especially true when fae or old gods are involved. For the enchantment that an old man, with too many jobs and not enough time to think, placed on one Harry Potter and Petunia Dursley, linking them together until Harry's 17th birthday, that time was now