I'm sure we're all familiar with the 'Oskar is the new Hakan' interpretation of the film (yes, I know this is the novel section, but bear with me) - while we know about Hakan's past in the novel, nevertheless there are parallelisms between the two (in the film, a strong hint of them being somehow analogous is with Oskar using the same plastic tube Hakan had used). One that I don't recall having been mentioned is that, before he pours acid on his face, he fantasises with Eli coming down, as an angel, to save him, to take him away somewhere where they can be together. Hakan expects to die, but dreams with salvation from Eli. Oskar in the pool also expects to die but is saved by what the witnesses later describe as an angel coming down to save him, and they go away together to an unknown destination. The only salvation Hakan gets from Eli is death (which by then he wants as a cure for all the ills of living, hence the references to Socrates and Aesculapius), but even this salvation does not end well; Oskar is saved at the pool, and gives up, and cuts ties with, his previous life - his old life ends abruptly, curing him of its ills. But this salvation (being with Eli) can eventually only be a mixed blessing - he cannot be with Eli without eventually at least aiding and abetting murder in some way, and somehow sharing in Eli's affliction, either by becoming infected himself or just coping with being at Eli's side (which is why I view the ending as supremely bittersweet).
Hakan did not start out as an Oskar, and Eli does love Oskar, but Oskar eventually becoming a sort of new Hakan - Eli's adult helper- cannot be ruled out even in the book. While an obvious and important difference between Oskar and Hakan is that Hakan is driven primarily by lust, and Oskar loves Eli and is too young for lust, my interpretation is that Hakan does feel some genuine affection for Eli, though his main motive is lust. While in the film there is no sign Eli has ever felt any affection for Hakan, in the novel Eli does seem to feel some degree of friendship for him, though he is primarily motivated by his need for a helper.
Another parallelism between Oskar and Hakan is a key moral difference between them and Eli: they actually have more choices apart from death. Oskar could have asked the adults for help (the one time he asks for help of any sort, the fitness training, he gets it without hindrance) ; he chooses to live in a world of violent revenge fantasies instead. Likewise Hakan had choices other than his (admittedly limited) indulgence of his lust. Neither one's options were particularly attractive, but they at least had some choice.
And please, lets try to keep this thread decent

, lest the wrath of the wolfchild be visited upon us.
Bli mig lite.