His+hanging+face,+like+a+devil's+sick+of+sin;

Throughout this stanza, the writer is clearly trying to give the reader some idea of the terrors of seeing a dying soldier. Among many descriptions of the complexion of the dying man, is "his hanging face, like a devil's sick of sin;" I think that this particular line, unlike the others, is not only trying to describe, but to terrify. One tends to fear what they cannot understand, and if there is anything that would be incomprehendable, it would be the devil getting sick and tired of sinning. Theoretically, he created the concept, he causes it, and he enjoys it. Imagining the illogic of it is scary. I think that is what the author is trying to convey, that he //can't// convey how terrible it is to see something like this.

The imagery is frightful, and haunting. Maybe the poet knows the readers probably won't see the miseries of war, so he sees it as his responsibility to teach us.