This trophy is cumulative. The easiest way to obtain this is to load up Chapter 2 > Lost Souls Locker.
- Beat the Drowned Sailor at the beginning, then head north through the open gate and fight another one, then a cutscene will occur.
- Head north through a gate once more and you will find yourself in an area with 3 doors. The east one will open and you must play through it as normal.
- Once you save that sailor, you will be facing a second door that opens. Do the same thing in here and when you get out, you will reach the final door; this is the one in which you will earn the trophy.
- During this Drowned Sailor battle, there will be Slithering Ruins that spawn indefinitely. Just chuck bombs with O and they will gather around and die. As simple as that.