Abomination is apparently a sequel to The Evil Maker, but watching it there really is no indication of this being a continuation of another story. In fact, because of the way the film is shot and the shoddy writing, it is hard to recognize a coherent story-line in this film, let alone trace it to another. It is not that the film is difficult to follow, it is that the film simply does not make sense.
The gist of the film is that the heroine is investigating a family incident that involves some supernatural activity at a cabin deep in the woods. In the process, she attracts the attentions of demonic forces who go after her little sister. The little sister might be possessed, or she might have a demonic doppelganger... or both. It is difficult to say.
The production value, even for an independent film, is awful. The film is grainy and poorly lit. You get the impression that the actors were handed their scripts just before shooting their scenes. Special-effects are done in a rudimentary manner, mainly glowing eyes and such. There are a couple of topless scenes which do nothing for the film.
The title is appropriate. This film is an abomination.