Disclaimer: I do not own anything Buffy or Harry Potter related. I just like to borrow them for my own amusement from time to time.
A/N: This is set after Season 7 of Buffy where Willow activated all the Potentials. For Harry Potter, it's set in between Order of the Phoenix and Half-Blood Prince.
They had joined forces after the spell activating the Slayers. And the Order needed all the people possible to fight against Voldemort. The previous Watcher's Council had decided that they had no part in what went on in the Wizarding World, but Giles was more than willing this time. Some Slayers, like Faith, went to Hogwarts to train as many as possible.
"Look here, Mister Potions-Are-Better, wands may work for you, but hand to hand still works. You'll need both if Voldemort decides to use vamps."
Snape smiled tightly. "I'll remember that, but my advice on magical uses still stands."