LostGod2000 has started up a Castlevania Fanon Wiki a couple days ago. If you ever had any theories on what a character's background might be, but don't have proof, or just want to make something up about them, perhaps the way they "should" be, this is a place you can go.
http://castlevaniafanon.wikia.com/wiki/Castlevainia_Fanon_Wiki