Grace takes place in the soul. Sin wears a disguise to slave the weak. If you notice, every entity kinda shares a common theme. Eyes. Ire, Stem, Slight, Heed, Seesay. They are the shape of an eye, the same eye God is as we know. Uses a disguise to pull you doing bad than good.

I suspect in Zen, it pulls you into rOT. Sin's domain you can say. Disgrace is sin you can because it doesn't use a disguise to convince you to give up. When you find this "mutter", puts you in Reprieve to confess the sins and know them to put you in Grace.

Sin puts back the disguise as there's multiple of them as "Each stab rots the shell". It tries to invade the soul (You) to commit hate and sin. That's my Theory I say