Need help with the achievement murder everyone and escape

[Asindrew]

SO i've killed every npc including all the guards, made sure every enemy is dead then escape the loop doing all 3 endings at the same time but the achievement isn;t popping. Can someone elaborate on how to do this? DO i actually need to kill every firefly aswell!? Or just make sure they are consumed? That will do my head in.

[ptor]

Killing everyone and everything requires eliminating (almost) all the monsters squirreled away in obscure passageways as well
I don't remember if you had to explicitly kill fireflies or consuming was enough, but by then I had enough energy gain that it didn't really matter so I didn't take chances and killed them ^_^'''

[Asindrew]

Ok thanks for the response ptor. I've definitely killed every enemy and every npc. Im going to try and kill every firefly now, which means Im going to have to make sure Im not consuming them, just killing. Thats going to be a headache lol

[demchrome]

So I just got the achievement and it took a couple hours to figure out... killed everything that can be killed except fireflies near the queen and the very first bunch where the loop starts. So I think fireflies are not needed for this achievement, but you do need to collect all the souls. They can be consumed in any way that is needed.
Here is the list in no particular order:
NPC
1. Assassin
2. Old man
3. Fisherman
4. Samurai
5. Drunk Guards
6. Firefly queen
7. Priest
8. Caporal
9. Chancellor
10. Necromancer
11. 7 Guards
12. Demon
13. Blacksmith
14. 4 Villagers

Monsters
1. 30 Rats
2. 39 Critters
3. 6 Beasts
4. 6 Hydras
5. 7 Fire bats

AND
16 Ghosts