Since the starting point of comparative analysis as defined here is the explanation of similarities and differences, the obvious conclusions to draw are: a. that universalizing comparative analysis is used to make sense of similarities, and b. that differentiating comparative analysis is used to explain differences.
There are three bonfires in the Tomb of the Giants. Two act as warping points. 1  Tomb of the Giants Warping Point-At the bottom of the third and last sliding bridge, down a nearby ladder.2  It is within the vicinity of Patches. Tomb of the Giants Warping Point-At the bottom of the third and last sliding bridge, down a nearby ladder. 2  It is within the vicinity of Patches.
Key is from an NPC in forest of the giants, in the area before where the second boss first drops off. Not the fog gate. 3.) Forest of the Giants second bonfire where the vendor is, break the wooden door and its above her. 4.) Lost Bastille, Deadman's Wharf side.