Kodi Smit-McPhee has been acting since he was a 10-year-old in his native Australia. He became known internationally in 2014 when he landed the role of Alexander opposite Andy Serkis in Twentieth Century Fox's Dawn of the Planet of the Apes. He used that to jump into another Fox franchise, joining the X-Men cast as Nightcrawler in X-Men: Apocalypse in 2016.

This summer, Smit-McPhee returns to his role as Kurt Wagner in the upcoming Dark Phoenix, which may or may not wrap up the franchise. SYFY WIRE spoke with Smit-McPhee about his thoughts on his relationship to his comic book mom Mystique and Kurt's internal struggles. The actor is frank about the fact that he's in a supporting role, but he takes his character very seriously, often sharing behind-the-scenes images for fan approval on his Instagram page.

In this interview, Smit-McPhee reveals the delicate balance he must strike between his demanding acting schedule and a potentially debilitating autoimmune disease he lives with. He has not only channeled that struggle into the development of Kurt's character but joins other actors like Selma Blair (who suffers from MS) who strive to be role models for others who suffer from ailments that the outside world cannot always see.

You worked with Bryan Singer on Apocalypse, but Simon Kinsberg directed Dark Phoenix. How was Simon's approach to the characters different? Any adjustments?

To be honest and the most humble way, I'm in a supporting role, which I'm honored to be. I think [Kinsberg] ultimately trusted me with what I was doing, and I trusted whatever he wanted to adjust. But he did help me by giving me that opportunity to express Kurt's darker side, which is something I really wanted to do.

In Apocalypse, it was hinted that Kurt's relation to Mystique might be film canon. Will we see more of that in this movie?

As much as I would love to push that, it's not something that we really have the time to express. If you are a deep enough fan and you do understand the origins of how these characters are connected behind the scenes, you could still view it in that sense. I personally believe from my point of view that [Mystique] is his mother and Azazel is his father. That's where I take the aspects of heroism and the villain in him, which is the kind of demonic aggressive side of Nightcrawler that he tries to transmute for goodness.

Something that we do see in the trailer is Kurt taking a pretty hard fall. Please tell us he makes it to the end of this film!

I can't tell you that. But I will say this film raises the stakes and it breaks the rules when it comes to what fans expect, for a lead character to always be protected to the end. I think it's going to break some of those rules, and personally I think that's something that needs to be done right now. This movie is a kind of quantum leap in terms of the tone of superhero movies, so it has to break a few rules. So I can't assure any of that.

Video of Dark Phoenix | Official Trailer [HD] | 20th Century FOX

Your recent roles, like Keda in Alpha, as well as Kurt, who was a gymnast, are physical ones. Did you have to put in any special training?

Honestly, I didn't do any kind of training. I have a muscle suit, and if I could wear that on red carpets, I would. I'm being open about this because, to be honest, I actually have an autoimmune disease that causes chronic pain and inflammation throughout my body. But it's actually caused me to shed greater awareness on autoimmune diseases and to educate myself on how to stay healthy.

It's a constant part of my personal life and basically, keep my career going and not feel like it could negatively threaten it. I just stay in a positive state of mind and try to stay as healthy and fit as possible.

That you for sharing that. Would you mind sharing your diagnosis?

No problem at all. It's called ankylosing spondylitis, or AS. Arthritis begins in the SI joined to the hip, and ultimately spreads throughout the rest of the body. In the West, doctors would like to tell you that there is no cure and you basically have to be a pharmaceutical patient for the rest of your life. And the drugs get worse and worse until you're disabled.

I [follow] Eastern and more holistic treatments, and there's a lot more hope there. I've achieved things beyond what doctors could even explain. Mostly through psychoanalysis and observing the traumas that are possibly repressed through being in the industry at a young age. In fact, these are all things that I pull from and I used in my characters and you can definitely see implemented into Nightcrawler specifically.

Thank you for being so open and sharing that information.

I think it's the right time to speak about it, because to tell the truth, I don't know where my life is going in the physical sense and I just want to enjoy every moment of it. And especially right now, where I feel I'm at the peak of my artistic creative expressions in the world is really correlating with what I'm expressing to the world. I want them to know the struggles that I also go through and the things that they can achieve.