hey do you think you could work in a bit of Blood Rayne, perhaps have her fall for a older Harry and/or you could even mix in a bit of Hellsing and have Seras/Ceres/or whatever her name is fall for Harry as well and find some way for her to become a dhampier from a vampire and of course Alucard could go for Lily. Hmmm...... also that girl that was turned in Hellsing that lived in the library Helena I think her name was could aged further than she is with Harry's or Lily's help as I never did like the idea of such a smal child being a vampire, you could even work it in where she gets adopted by lily and/or gain some type of magic from feeding from either Lily or Harry. With a crazy setup like that you could also have the Potter's aligned with Hellsing till all their trouble is over then have Hellsing help the Potter's out with MoldyShorts I mean can you imagine Alucard, Harry, The Weasley Twin's, Sirius and Lupin at Hogwarts can anyone say one hell of a prank war LOL pardon the pun but you could have them drive Dumbledork batty quite literally.