I had no problem with soul arrows sorcery. Hit the warriors that are visible, ignore the invisible. Then go talk to the cat inside the ruins. Everything will look peaceful after. :)
Rheinmetall's forum posts
In case you were a bit confused from the comments, to sum it up: 1. Go down to the Abyss via New Londo Ruins. 2. There are three new areas that will be unlocked after you complete the Abyss. 3. The Abyss requires a certain ring to be equipped.
Unless you are a formidable player, by all means you need magic in order to survive. If I were you, from now on I would do some crazy soul farming and improve the attunement stats so that you can equip at least three magic spells. Pyromancy for powerful close combat hits, or Sorceries for weaker but ranged attacks, it's your choice.
You need to play it online and consult the messages that other players left. That's what I do when I get stuck.