you have to be cursed to damage them. Either have the frogs in the depth curse you(wouldnt advise that strategy) or use that item called the exercist curse or some name like that. once you use that item, you can them damage the ghost as you would a normal
enemy, with item, melee and magic. My advice to you is to take a bunch of fire bimbs with you. you need to run and make them all follow you into a wide open area outside and when they are all following you and all bunched up together. You throw a fire bomb
at them and you can probably kill them all with two of them.
He's talking about "Transient Curse" items. Those are the items which bestow a temp. curse on you so you can damage the Ghosts. Purchasable for 4000 souls from the female merchant in the Undead Burg and also are found at various places in New Londo.
I'm only level 22 or so and the only problem I've had with the ghosts was them whacking me safely through walls while not allowing me to hit them back. I got as far as the group of rooms right of the ledge just past that bridge where they are all hiding
beneath. but after going in it was impossible to tell who was hitting me or how many of them there were... just a bunch of f***ing arms coming throught the wall. Oh - and the stupid temp curse wearing off in the midst of battle - that's fun too -
yea, thus why i have the curse item equipped for when it wears off. If I was you guys, id avise you to wear light armor. You need to be as mobile as possible. I be jumping and dodging like crazy in there. making them follow me and then take care of them
with the bombs outside behind the building. But I got it down to a science now, I can get through the entire place from the entrace to the out of the back of the building and kill most of them without getting hit or getting hit once or twice.