Robbie is Hollywood's It girl of 2016

Harley Quinn was meant to be just a sidekick.

Yet, the wacky accomplice and lover of the Joker quickly rose in popularity to become one of the most iconic Batman supervillains in the DC Comics universe.

Compared with notable Batman baddies such as Catwoman, Riddler, Two-Face, Penguin and even the Joker himself, Quinn is a newbie. She was created only in 1992 whereas the others came into being in the 1940s.

The buzz surrounding her is understandable.

The former psychiatrist is crazy, insanely hot, dangerously fun and incredibly gifted. And now, fans will finally get to see her in a live-action movie.

Margot Robbie, who plays Quinn in new supervillain flick Suicide Squad, is somewhat like her big-screen alter-ego.

The 26-year-old Australian's Suicide Squad co-star Will Smith, who also acted opposite Robbie in last year's crime caper Focus where they played con artist lovers, was instantly bowled over by her acting prowess and down-to-earth quality.

WHO'S THE STAR?

Smith, meant to be the leading man of the David Ayer-directed movie, professed that he knew Robbie would be the star of the show the moment he saw her step out of the trailer in her Quinn get-up the first day on set.

"We all knew immediately that Suicide Squad (was going to be) the Harley Quinn-Margot Robbie movie. She was spectacular," Smith, 47, told M at the Moynihan Station in New York City where the cast met the press.

The veteran US actor plays Deadshot, the deadliest and most accurate marksman in the Batman world.

In the movie that's an offshoot of Batman v Superman: Dawn Of Justice and a part of the DC Extended Universe, Deadshot is the de facto leader of Task Force X, a team of death-row supervillains - including Cara Delevingne as Enchantress, Adewale Akinnuoye-Agbaje as Killer Croc, Jay Hernandez as El Diablo, Adam Beach as Slipknot and Karen Fukuhara as Katana - who become a government black ops squad in exchange for clemency.

Apart from joining in the fight against a greater threat to humanity, Quinn is also trying to reunite with her lover, the Joker (Jared Leto).

TEAM SQUAD: (Above, from left) Viola Davis, Will Smith, Margot Robbie and Jared Leto at the Suicide Squad world premiere. PHOTOS: REUTERS, WARNER BROS

Opening here tomorrow, it also stars Viola Davis as Amanda Waller, the US intelligence officer who creates Task Force X, and Joel Kinnaman as Rick Flag, her right-hand man.

For Smith, having Robbie getting all the limelight was "a freaking relief", as he does not have to carry the box-office burden entirely on his shoulders.

"(The 1996 alien invasion blockbuster) Independence Day was my last full-on ensemble movie, so this for me is awesome. You don't have to be in every scene. You actually can sit in your trailer and you can go home some nights," he said.

If Robbie knew she was the next big star of the DC universe, she was certainly not showing it.

Casually dressed in a blouse-and-pants shirt combo and sporting flat sandals, the pretty blonde sat cross-legged on the couch next to Smith, exuding an easygoing yet sexy vibe.

On being hailed as the It girl of 2016, she said: "I'm still pinching myself that so many good things are happening to me. I just hit the lottery.

"I know I worked really, really hard, but I know other people have also worked really hard and haven't had these opportunities too.

"So all I can do is be extremely grateful and stick to the plan, which is to work with really good film-makers like Ayer..."

"She is just being modest," Smith interrupted, adding: "Margot has a superpower that humans rarely possess. There's a thing when you look at a person and they make you feel better, make you want to be better. I've seen it a few times in my life. It's magnetic, and I'm excited to watch her get a hold of her superpower."

Squeezing Smith's hand, Robbie whispered "thanks, that's so kind" to him, and you could almost see tears in her eyes.

There's no doubt that bringing Harley Quinn to life will put Robbie on the upper rungs of Hollywood, boosted by her critically-acclaimed performance as Jane in The Legend Of Tarzan, which is still showing in cinemas.

CONNECT

Robbie reasoned that Quinn's popularity could be due to people, particularly women, being able to connect with the character.

"Harley is real in many ways. She is strong yet weak. She is in an abusive relationship with the Joker yet she loves him dearly.

"I know women who are in abusive relationships. I've got friends who keep going back to the boyfriends who cheat on them. And you sit there going 'why'?''

Robbie, who has been dating British assistant director Tom Ackerly since 2014, added: "There are tons of people in scenarios like that. It's not about playing a strong character but playing a real character, and a character that people can relate to because they are humans and they have flaws. They make mistakes."

Even though it was "embarrassing" for Robbie to wear Quinn's tarty costume, it fit the character "to the T".

"To be able to change out of the boring prison outfit and put on those sparkling hot pants was like Christmas morning," she said.

Smith replied: "You know that Harley Quinn get-up is going to be the Halloween outfit of this year. Every little girl is going to be Harley Quinn..."

"And that will be (every) mother's nightmare," added Robbie, laughing.