@northernnarwhal I killed it with a longsword. No necromancer around. You get the key from the map guy, Go through the door behind the fat armored guy after the bonfire with the merchant hag. Stand on the tree ramp near where the eagle drops the big guy, and jump down to a wooden thing that connects with a roof. From the roof jump over a hole towards another wooden platform, you should see a cave in the back. Enter the cave and be careful with the boulder that'll roll down. Go the way the boulder came from and you'll find a guy, talk with him a lot and he'll give you a key.
