Hi Vithaya, your role in Only God Forgives is one of the creepiest and nastiest in recent cinema. What qualified you for the part?

I run a successful ballet school in Bangkok, my wife is a ballet teacher, and I have managed the school for 19 years.

Oh. So how did you get into acting?

This is how I start my acting career. About five years ago, I went to a party and a cameraman saw me and asked me to act in his short film. I said sure, why not? After that the same cameraman got a job on a Hollywood movie shooting in Thailand. That movie was looking for a character of a king, but the director couldn't find anyone she liked. They said: "Hey, why don't you come in and read the dialogue."That's how I got my first movie.

That's The Prince & Me: The Elephant Adventure, I take it?

Yeah, it's the sequel to The Prince and Me. Then I started doing small parts in international productions. In Hangover 2 I had a tiny part at the end as a priest. That was fun.

Must have been.

I have never done Thai soap opera or Thai movies, so my style is very western, very small movement but all about the energy. This casting director said to me, a director from Denmark wants to do a movie in Thailand and your style would fit perfectly with his script. So we made a tape and sent it to Nick, and Nick liked it. I thought, wow, this is special because Chang was not a small part at all.

But this was before he made Drive, right?

Right. Back in 2010, the original idea was that Luke Evans would do the Julian part, but then Ryan said he wanted to do it, but he had to do Gangster Squad first. Meanwhile, I'm sitting in Bangkok, waiting for it to happen. Then Nick said he would do Only God Forgives next, and in my mind I was sure they were not going to use a no-name Thai actor like me. Nick just won Cannes, Ryan is a A-list pinup Hollywood actor – they're going to recast and get someone famous. But when Nick came to Thailand, at the end of 2011, we met in person and he said he really liked me.

Were you intimidated when you found out you were acting opposite Ryan Gosling?

I thought: am I dreaming? Is this happening to me? Like I say in the movie, God would not give you something you can't handle. On the first day we are introduced at the production company, they were having a kind of Hindu ritual ceremony. In Thailand we do this, just to bless the start of the movie. It's a prayer to Ganesh, very spiritual, everybody wear white, fragrant flowers everywhere. Ryan comes in this big van, they sat me next to him. He's half asleep, wearing his big black glasses. Then all of a suddenhe turns to me and says: "Hey, I heard you make good pad thai fried noodle, right?" Then we get on very well! He was super down to earth. It released a lot of stress for me.

You do a lot of sword slicing in the film. Can you handle one in real life?

I'm a fifth degree black belt in kendo. Japanese fencing.

So that would be a yes. How do you feel about the violence in OGF? It's pretty intense stuff.

The way I see the violence in OGF is this. Nicholas create a feeling, with the foreplay – you know he always call himself pornographer, right? – the way he build up a scene. It takes me just three seconds to cut someone eyes out, but the scene is so effective because of all the buildup that happened before. For me, Chang is an angel of vengeance. He's basically a character who has responsibility to protect his kingdom or his country, his people, so his violence is not for hate, or some kind of discrimination – it is punishing people who have a bad karma. I look from the eastern philosophy point of view: you show people being punished for what they did. Billy and Julian, they think they can escape from their karma – but you can't, you have to pay for it.

The karaoke scenes are particularly frightening. You sang them all yourself, I was told.

You know, I love singing at party, but never become a professional. This character, when he sings karaoke, he is not entertaining people, or making people happy. He is not smiling or enjoying himself. Symbolically the karaoke is the place he purifies himself after all the madness.

Has the phone been ringing off the hook since you made the film?

Now Thai film makers are scared to ask me because they think I am too expensive as I have done a Hollywood movie.

But I say: I am looking forward to working with good directors in Thailand. I'm not saying I'm picky but since OGF I only accept good offers. You know, at my age you are either semi-retired or picking up grandchilden – but discovering this new job, it's fantastic for me.

• Only God Forgives is available on Blu-ray & DVD now