This anime was adapted from a manga by Okamoto Lynn, the author of Elfen Lied, and it contains very similar conceits: a powerless male protagonist trying to help a bunch of girls with dangerous powers, who are pursued by sadistic and vicious hunters. Clearly Okamoto has a particular story he wants to tell, and with the recurrent themes of powerlessness, victimisation, exploitation, and alienation, it makes you wonder what he went through in life.
Anyway, I have a soft spot for these kind of thrillers that put their effort into tricky confrontations, so I enjoyed it a lot. Unfortunately the ending is extremely sudden and inconclusive (they ended at a minor ending in the manga), which was disappointing given how things had developed so far. I’d like to see more.