I found the ring and I also found out that the lightning caster falls down if I fire enough arrows at him. But it cost me some attempts to cross the bridges in one piece, since I am notoriously bad in not
falling to my death all the time. Most of my deaths in Demon's Souls were because of me falling off a cliff after all. Also, I found that nice lightning spear after poisoning the mimicry.
Anor Londo is pretty pretty I have to say, so far I only encountered those giant knight-people which seem to be quite vulnerable to fire. Having pyromancy ready makes life easy sometimes