loghaD:
Clouds don't just produce rain; they become the rain, or at least parts of them do. Similarly, the blood of the soldiers is both the source and the emanation. However, unlike the case with clouds and rain, we tend not to use different words to distinguish between blood coursing through a person's veins and blood flying through the air, so "the soldiers' blood" fits as both the subject or the object.
I understand this argument, and indeed it offers an explanation, if we understand the {SIStaHvIS negh 'Iw} to actually be {(negh 'Iw) SIStaHvIS negh 'Iw}. But is it this the case here? The thing which confuses me is that according to the klingonska article, if the thing which is being rained down is anything "unusual" then one would expect it to appear in the object position, not in the subject. ~ Dana'an