Bab 857: Cap 855: Recycling souls

It's been 3 days that we've been in these endless battles against those damn birds, I'm sure I faced the same enemy at least 4 times during that time, it was the same big Harpy that kept summoning more bird monsters. 

When I asked this of my other companions, some realized that something like this was happening to them too. 

This made me think that the Dungeon was somehow recovering the souls given to the monsters, but I couldn't say how, as far as I've learned a Dungeon can only take a soul from someone dying inside the Dungeon. 

These monsters even if they came from this Dungeon are dying outside, how were the souls being guided back to the Dungeon?