I am in the process of outlining a novel; The King of Maggots (KM for short). KM is centered on Vladislav Tepes, IV, the illegitimate son of Dracula (Vladislav Tepes III) and Wilhemina Harker and the ordeals he undergoes. From losing his claim to the throne after his father's death and the end of the official royal bloodline; to the constant resentment he has for the double-whammy of betrayal his wife served him after arranging the suicide of his best friend and fooling him into raising the child of her affair; to his later exploits based upon the mental, emotional, and physical degradation of women and how he built a fortune for himself upon the art of seduction alone. That's all well and good and established. What I have a problem with is the ending, or the lack thereof. In Option 1 for the driver of the plot, Vittoria Augustus, unexpected heiress of a wealthy architect, is lured to Vladislav's residence on the pretense of finding a lead on the disappearance of her best friend Elizabeth. Vladislav's past is revealed either with flashbacks or through his journal, which Vittoria ends up reading. Toward the end of the novel, Elizabeth turns out to be alive and presents herself to her old friend after escaping the burial chamber, attempting to save Vittoria by killing Vladislav whilst he is stunned. But Vittoria kills Elizabeth instead before she recognizes that the disfigured, grotesque form used was/is her best friend. In Option 2, a butler named Calypso narrates Vladislav's life from a third-person limited/first-person-ish perspective and recounts the tales of the most notable women from Vladislav's case history, right up until the point that he [Calypso] commits suicide. In either story, there isn't the type of resolution that's present in most books. In most books the character comes full circle in some way or the original problem is solved, even if it doesn't lead to a happy ending. But in this story, the villain, Vladislav who is the entirety of the problem, is never "solved". It can safely be presumed that he keeps on trucking long after the story's ended even under outrageous or seemingly tragic circumstances, because that's just the kind of guy he is. Is this okay? Is it okay if I don't "fix" the villain in some way before ending the novel (and I don't plan for a sequel)?
This should be fine, as long as you wrap up other problems - characters, the basic plot, etc. It can be unsatisfying in a sense (your villain not being conquered) but only very few people will like a completely unsatisfying ending, so make sure there is some hope and/or closure for the other main characters.
I admit I didn't understand the entire post, but as for the title question, you could think about what you want to say with this story and what you want the reader to walk away with, and shape an ending around that?