Board Thread:Theories Discussion/@comment-99.102.153.9-20150221222752/@comment-173.21.55.4-20150912181407

That's probably because otherwise the sinners couldn't be killed if they hadn't come in contact with the wrath vessel. The sinners would be magically healed of mortal injuries, so they would all be theorically immortal if another vessel didn't kill them. Why that was always Grim the End has to do with the nature of wrath itself.

It makes sense that wrath would be what kills off the other sinners because wrath is closely tied to revenge. All of the other sins are like character flaws, for lack of a better word, but wrath is the flaw that punishes other character flaws. Mothy could have had Venomania killed by the someone with the Marlon Spoon, but that wouldn't be as symbolically significatant as being killed with Grim the End, as if wrath was in some way bringing justice.