This past weekend in Los Angeles, actor Rodrigo Santoro sat down with members of the press to discuss what it's like playing a self-professed God in the upcoming Warner Bros film "300." In the film, Santoro plays the Persian emperor Xerxes, who's dreams of ruling over the entire world are met with a lot of resistance from the Spartan King Leonidas, played by Gerard Butler. Despite Xerxes' larger than life presence (both literally and figuratively), Leonidas will not surrender to the God/King, which lays the ground work for one of the most important military battles of all time. CBR News was there to talk with Santoro about what this role means to him.

Being evil ain't easy, but for Santoro, playing antagonist Xerxes is pretty damn fun even if the audition wasn't simply the "take off your clothes" process that some expected. "Totally different," he laughed. "I was back in Brazil shooting a film and one of the producers of the film, Gianni Nunnari – who is Italian and has been to Brazil many times and was aware of my work in Brazil – brought up my name. He asked me to come to LA and audition for this part. But I was shooting something in Brazil and I could not come. So, he said put yourself on tape. I did that, but I was shooting something in Brazil and in order to play that character I had to lose about 35 pounds.

"They saw the audition tape and they really liked it, but they said, 'he's too skinny.' I said no, I'm just shooting a movie where I have to be like that! So they decided to do it and in four months I came back a giant."

Even a giant has to deal with the challenges of blue screen technology and Santoro described the experience. "It was a real challenge because I'd never done anything like that, working with the blue screen work. With blue walls and nothing around you. We did have the graphic novel as a source, as something we could use to inspire ourselves, but when you're working, there's nothing around you.

"I found it was great training, a great exercise to live in the world of imagination completely. It required a lot of concentration. Every I time I stepped onto the set until the time I got back to the hotel, I would just try to be in character the whole time and it was a lot of work just to stay concentrated and keep that energy."

Seeing the "300" graphic novel for the first time was a revelation for Santoro (he'd seen "Sin City" previously), who saw his character as larger than life because of Frank Miller's vision on paper. "When I first saw the picture [of Xerxes[ I was salivating, because I thought, 'my god, what a character.' And he has a soul already, he already exists. It's not just a drawing – it's something else. There is a soul in there. So what I tried to do was just bring it to life. But regarding the way he moved, because Xerxes is such a self-proclaimed god, he's someone who believed to be above everything and everyone on the planet. Sort of this ego trip where he's beyond everything. I would try to work that angle with my body language. I think it's important for this character in the way he carried himself in order to portray this God-King of Persia. Just smooth, but at the same time carry yourself as a god. How would it be? It wasn't just standing there with your chest out, it was a little more subtle than that. Trying to find the right feeling and asking yourself, 'What was it like to feel like this god?'"

To enhance his knowledge of the world he'd inhabit, Santoro sought out other sources of information on Greek myth and history, hoping to add nuance to his performance. "I read a lot of the Greek historian Herodotus who I found was the best source. I think it's a great combination of reality and fantasy here, because we do have historical facts, but the way we tell the story is hyper-real. It's fantasy. But yeah, I did a lot of research and there were some things in Herodotus that were very interesting for me to build Xerxes. One of them was the fact that Darius, Xerxes' father, had more sons, but for some reason the power went to Xerxes. It's controversial, nobody knows exactly why, and Xerxes has a very famous sculpture in the palace of Persepolis that faces the statue of Darius, his father, with an inscription saying that he was his father's choice. I think that just tells us that he was pretty insecure and ultimately weak. That's why I think he put out that figure. I don't know, maybe that's where Frank Miller took the inspiration to build Xerxes like that. Just this sort of god and more of a ruler-tyrant style, but I see him as very insecure and weak underneath, who just put out this god figure in order to protect himself."

When Santoro saw the massive throne upon which he would sit, he was immediately in awe and explained, "When I saw that huge golden throne and carriage and actually stepped on those guys' backs, I asked, 'Do I have to do that?' Yes! It was a real trip.

"I remember I had this velvet blue cape, which was very heavy, plus all the chains around my neck so it was like, wow, that is a lot to carry," continued Santoro. "I was having a hard time coming up the stairs and down, not stepping on my cape. So, this was just a joke, don't get me wrong, but I clapped my hands and said, 'Don't I have a helper? Someone to carry my cape!?' So this guy walks out from the costume department and says, 'From now on, I'm your helper.' He was always carrying my cape around. I felt bad for the guy."

Adding to the experience was all of the makeup and jewelry, which helped to set the mood for Santoro and put him in the Xerxes mindset. "The costume helped a lot," he explained. "The gold is sort of part of him. The makeup was a long process, like four to five hours every day – which was actually great for me because it was my time to get into the character. It was sort of like a ritual. I was taking that time just to perceive it, just to dive in and get into the character. All that helped a lot, especially since I think this character is on a little bit of an ego trip [laughs]. Those four and a half hours [each day] were a great opportunity to be with myself and be tripping and just make it all about me. I would have my earphones on and I was in a different dimension, I was in a different world. I was in his world. That's what the character's about – it's about his perception of reality, which is just his reality. It's not the reality that corresponds to the other characters, it's his reality."

Sadly, Santoro was told that he wouldn't be allowed to keep the costume. "I did ask. They said no. I thought it would be interesting to have. With all the characters I play, I always ask for something, but this one they said no, not anything."

Playing a character that self-involved and power hungry without seeming evil is a challenge for any actor and Santoro remained cognizant of that challenge throughout the entire filming process. "Very tricky, man, very tricky," said Santoro of not making Xerxes the typical mustache twirling villain. "At the same time I was like wow what a character, but on the other hand I was like whoa my god, this is going to be so difficult. I just made a choice. I tried to make him a little ambiguous. A little lighten up here or there. More an entity than a human. I don't think he's human.

"I didn't want to play a caricature even though we were in this comic book world," said Santoro. "It had to be believable, so you just have to go for it. I think all of the actors in the movie sort of did the same. They said let's go for it and try to tell the story."

For those not in the know, Santoro is also working on the hit television series "Lost," as Paulo, but he couldn't reveal much about the experience. "If I say anything about it, I have to kill you. Because I don't know anything!

"The 'Lost' experience is very unique as well, because you do not know what's going on," continued Santoro. "You really do not know what's going to happen until two or three days before. It depends, sometimes you'll get three or four, sometimes a little bit more. Since I just joined the cast, I don't know my backstory. There's no building a character like this. It's upside down. You have to live the moment."

"Lost" co-creator JJ Abrams is a big comic book fan and did discuss the film with Santoro on the set. "Yeah, we talked. He said he was really excited to watch. I said yeah man, you really gotta watch!"

As for the doors this film opens up for Santoro, the actor said he's not sure because the film hasn't been released yet. "The response has been amazing. I don't know, I hope good doors. What I really hope with the film is that people go see it and that it's a very wide audience that sees it, not just people who are into graphic novels. I think it's a great ride, it's a great experience. It's very original. I've never seen anything like it. So, even though you may find it very violent, it is an interesting ride and that's what I hope people get from it."

CBR's Arune Singh and Andy Khouri contributed to this article.