| As always, I'm going to start with the smaller things, and work my way up, so it doesn't look like I'm straight out attacking, plus you'll have something to fix if you don't want to go for the bigger ones. With that said, there are a few things that threw me off, the first one was that the first couplet doesn't rhyme (enemy and boundary), and same with horizon and corazon. In the first line of the second stanza you're talking about a single being, yet in the second line it becomes plural (sniff a being somewhere/all I can think about is their blood), I would probably change that to either its blood, or her blood. Simple things like that appear in quite a few places, which distracts me from the poem itself.
The rest is somewhat ok, I mean the story is interesting, but the poem doesn't really flow like it should. Perhaps it's just me, but I couldn't find an actual beat to it. I'm used to reading poetry that goes something like ta-ta-ta ta-ta-ta, and is consistent with it, but your poem changes from line to line. One way you could fix that is by having each line roughly the same length, and it'll flow much better.
I'm off to work right now, but I'll continue when I get back. | 
