I finally managed to get Excalibur thanks to all the info I found here. I actually didn't kill Nessie because I was having a heck of a time with that. Instead I had planned to sneak by her or a least part of the way then make a mad dash for DJL. On my second attempt I was able to find the mythical sword. I was going to then fight her, but I realized that I could just teleport out and so I did. I'll save that battle for later. My guys are a bit low (level-wise) right now.