Colin O'Donoghue, <em>Once Upon a Time</em> Colin O'Donoghue, Once Upon a Time

Don't expect to see a Dark Supercouple anytime soon.

On Sunday's Once Upon a Time winter finale (8/7c, ABC), Dark Swan Emma (Jennifer Morrison) will once again try to reason with her boyfriend, whom she had to turn into Dark Hook (Colin O'Donoghue) in order to save his life. "Hook is so angry with her for doing the one thing he asked her not to do, turning him dark, when he knew he would have no power over it," O'Donoghue tells TVGuide.com. "He's like a really pissed off-boyfriend."

That said, Hook's feelings for Emma make the situation complicated. The actor says, "You'll get to see some of that in this week's episode. You see with Rumplestiltskin and Belle and even with how Emma is with Hook, they still can love even within that darkness."

Unfortunately, no one can hurt us as well as our loved ones. They know your weaknesses, what matters to you the most, and unfortunately, the episode description promises, "Hook's actions will devastate Emma in a way no one saw coming." Just great.

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Check out the rest of our interview with O'Donoghue and watch the sneak peek of Hook confronting Rumplestiltskin (Robert Carlyle) at the end:

Hook left Excalibur behind on the ship where he dueled Rumple. Will we see Excalibur come back to haunt him?
Colin O'Donoghue:
Excalibur is the only thing that can kill him. He left it behind. That's a very dangerous thing to happen. Excalibur is definitely something that Hook is aware of and it plays a bit of a part in the episode.

Opening a portal to the Underworld doesn't sound too safe. What sort of fallout can we expect from opening the portal?
O'Donoghue:
You saw that the object was to bring back all the Dark Ones into the real world. Hook knows that the darkness is using him to get what it wants. As long as he gets his revenge on Rumplestiltskin, he doesn't mind that he's being used. And he might be blinded by that darkness, if you know what I mean. He essentially doesn't have control over it.

It seemed that his revenge against Rumple was to kill him, but now it involves the past Dark Ones?
O'Donoghue:
They want to open a portal to the Underworld essentially and banish people there, which eventually -- I can't reveal too much in talking about it because it's part of the second half of the season, but it's worse than death.

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Fans are loving Dark Hook! What do you think the appeal is?
O'Donoghue:
I guess it's similar to who Hook was when he first came on to the show. [Dark Hook] is slightly more manic and a little bit crazier and darker. Sometimes people like the bad boy. He's fun though for me to play. Maybe people are enjoying that side of him when we've had so much of the last season or so when he was trying to become a good person. It's always interesting to see somebody struggling with two different sides of their personality.

It was also hilarious to see Dark Hook impersonate Rumplestiltskin.
O'Donoghue:
Yeah, what happened was that when I read that scene, I remember thinking that that was one of the first things that Rumple says to Hook. I know it was like my first time on the show, and so I thought it would be funny to try and do it exactly like he did. It was also a good jab at Rumple, who is no longer dark. The thing is that once you taste that darkness, it's hard not to want it.

Hook has magic now. Will we see him perform more magic?
O'Donoghue:
Yes, you'll see a little bit more magic, not a huge amount. A few more with the red smoke, which is nice ode to the Disney Hook.

How prepared are our heroes in Storybrooke for what's coming?
O'Donoghue:
I mean, how can you ever be prepared for all the most evil people in history coming back to Storybrooke? They're as prepared as ever. But then they've fought snow monsters and wraiths, so it's safe to say that they shouldn't be surprised by anything.

Once Upon a Time airs Sunday at 8/7c on ABC. Check out a sneak peek of the winter finale below: