Man, what a fucked no good ending situation this is. Yet, strangely enough, I find this warped relationship between Pedro and Manuela to be kind of "beautiful". With Pedro you have a guy that is actually pretty decent at heart, yet he gets angry easily and is abusive. But, as screwed as it's been, he has been trying to help her. I think the line about how he welcomed her back several months later without any anger, was a great one for me. As well as the moment with him crying as he gave in and gave her the needle. And, of course the line about their "first loves".
Now, does this make his abusive actions and things he did to people like Helena okay? Of course not, but the important thing is that these three chapters went a long way to present a very three dimensional character. My time with anime has taught me that this kind of in depth treatment for a "villain" is very rare. I have nothing but respect for what Edo has done here.