Also, when you get up the battlements, there's a hidden bonfire. A few areas will be scarred by burn marks. You're looking for the area with a corpse and an item sitting near the mark; there should also be crumbled battlements. If you drop down from those broken battlements gently, you'll come to the bonfire.
And in case you're referring to multiple titanite Demons, yes, there are four in total. They're spaced out, though, so you shouldn't have to fight more than one at a time.