All Bobucles recommendations are spot on. I flattened the area with a hoe, built a spiked wall enclosure around Bonemass' altar, to keep adds out and even put single roof piece campfires along the inside of the wall for quick rest, stamina regen. The wet debuff kills stamina & health regen, and the mace is the weapon of choice against virtually all swamp mobs except Abomination (which really hates axes).