Edward has been presented as the story's villain from the first chapters, and certainly he's done some bad things, BUT... really, when you step back from a distance and look back over the story, has he really been THAT wrong?
For example, the characters he seemed to be the most unfair to and unreasonably suspicious of, like Kate, Maryrose, and Christopher/Anthony, actually turned out to have ulterior motives, after all - not necessarily evil motives, but they certainly weren't who they seemed to be, and were definitely all up to something that Edward wasn't in on.
His sidekicks Eileen and Gerald don't really seem to be bad sorts - their scheming with Edward mostly seems to be coming from a place of being in a perilous situation where they can't trust anyone, except for each other, in much the same way that Kate and her friends have had to make some tough choices but have maintained their friendship through it all.
And Edward's motive, if it can be taken at face value, seems to be a combination of having something to prove because he's found little else in his life to feel proud of, and what seems to be a genuine devotion to the Grandfather, whether that loyalty seems to have been earned or not (we've been given no explanation, yet, for why Edward seems to be so loyal to the Grandfather, in a story where we have no reason to think the Grandfather ever bothers trying to interact with anyone so low down the organizational structure of the house.)
In short, Edward's a misguided character, with a flawed personality, who has made some terrible choices, but he's made his choices from a very difficult situation, and apparently a position of weakness that might have gone differently, with the right reinforcement and encouragement for his more positive qualities, the way that Patrick/Ricky, the Belles, Barbara/Barbie, and so many other characters who started as antagonists have gone differently with just the right push.
I was just re-watching a couple of the later episodes of the anime's second series to refresh my memory on something, and incidentally noticed that blink-and-miss-it flashback scene where Christopher/Anthony first organizes the children's wing with training, in the backstory before Kate and Emilico's day, and Edward is resistant the whole idea, scoffing at the suggestion, until Christopher nominates Edward as the first instructor, to teach art and music, which seemed to change Edward's personality completely: of course, it probably inflated his ego a little, that would be completely in character, but there's something else there, too, that hints that Edward responds positively to a little respect and a genuine compliment for something that he really does seem to do well, which seems to be Edward's whole motive for promotion to the Third Floor to begin with: to be recognized for doing something right by someone he respects.
So, that's a round-about way of saying that Edward might well be an asshole, but he doesn't seem irredeemably evil, at least not yet, which means a lot in a series where just about every character has revealed some hidden depths, and most of the villains have, sooner or later, turned out to have good qualities as well as bad ones.
And, I'm probably not the first one to suspect that, because someone took the time to highlight these lines from Edward on a webpage with quotes from the characters of this series:
"Sometimes the most important things in life are the things we can't see." - Edward
"In the end, it’s the relationships we build that matter most." - Edward
Also, as an aside, how many of us noticed on any viewing of the anime or reading of the manga the detail that one of the first members of the research team was Edward's sidekick, Gerald? I never noticed that before, just caught that in the flashback scene I mentioned above. It's (probably) not a significant detail, plot-wise, but interesting to me, nevertheless, because I'd never stopped to wonder very much about who Gerald and Eileen really are, what they were like before unification with their shadows or even before they were sent to the Shadows House, or what this series might have looked like from the point of view of Edward and his friends, if we'd started with them, instead of Kate and Emilico. Something tells me we might end up finding out, as we're surely in for at least one more flashback scene for Edward's past, to set the stage for the rest of his character arc, whether he ends it a hero, or a villain....