Up until Sunday's episode of "Game of Thrones," the Night King had never said a word and the show never fully explained his motivations.
Was Maisie the actor you were closest to on set?
This character made your face infamous around the world.
Exactly.
Yes, Maisie was one of the first ladies who knew who I am, because many of the actors didn’t know. I did a couple of fights against some actors in a different costumes as a stunt man, but I prepared Maisie for the fight with the small sword and the big sword in the courtyard with Brienne, I spent hours and hours with her on that dance.
They asked me if I wanted to be the Night King because they liked my performance in season 5 when I was fighting with Jon Snow and he killed me in the cottage. After that episode they asked me if I wanted to play the role for season 6 and I said yes why not.
What did you think of this Sunday's episode, it was a big one for you?
No, I don’t need to say anything because I kept running everything through my mind.
This was one of the hardest days of my life. It was raining, it was cold, it wasn’t easy for Maisie to jump at the right time, it wasn’t easy for me to grab her at the right time, it was the most difficult thing to do in front of a camera. I did many difficult stunts, running through fire, many crazy things. But this moment with Arya when I grab her, and the emotions from Maisie were so strong, I felt like I spent all my energy that day.
What do you think was the Night King's motivation in the end?
It’s not a fun life.
After that shattering conclusion in which Arya stabbed the evil leader, causing him to disintegrate into a million pieces, we may never know why he wanted to annihilate the living.
Because somebody, many years ago, made some mistake and he became the Night King, and he didn't want to be the Night King.
Did you ever want to say anything on the show?
What was it like shooting that final scene with Arya?
Furdík, who was previously a stunt man on the show and only started playing the Night King in season 6, revealed the white walker's darkest secrets.
SPOILER ALERT: Do not keep reading unless you’ve seen “Game of Thrones” Season 8 Episode 3, titled “The Long Night.” 
My daughter, she is very critical of everything I do, and she just said, "Wow, that’s unbelievable," and she was very happy. When I saw this I said, "Oh My god." The music when I’m walking to Bran, it was amazing, I was so proud to be a part of this show. She is always critical when I am a stunt man and fight, but if she loved it, for me that beats what anyone else says.
I was so happy to have work, especially in this business. Now we do. Nobody knew how this character would grow up. As a stunt man, many times directors asked me if I wanted to play small roles, until season 5, nobody knew how big this role was. It became bigger step by step, people started to talk about the Night King from season 6.
What was going through your mind when you were playing the character?
He’s tired of living out there in the cold and the snow.” /> He was like now I have a way to go to war. Now I kill everybody because you made me the Night King and made me live seven or 10 thousand years behind the wall in a cold country.
With the costume and the makeup you already are the Night King, the makeup changes you, it helps you so much. Because I wasn't an actor, he gave me a lesson on how to play. He said, "I would like to see your tears, just play with your face." He gave me many tests and directed me exactly where to go. Afterwards my homework was to go to the hotel and cry in front of the mirror. Miguel Sapochnik [the director] also made the job easier for me. We had many discussions before in the office.
He wants revenge.
However, Czech actor Vladimír Furdík the man behind all the makeup and prosthetics, told Variety that the Night King's motivation is clear: "revenge."
You just used your face to express things.
Revenge for what?
How did you score the role of Night King?
Easy, I picked up the phone, somebody said, ‘Hey Vlad, do you want to be the Night King,’ and I said, 'Yes!'