CNN  — 

Hwang Hyo-kyun deceives people for a living. The more his audience notices his work, the worse job he’s done.

“The fact that we can get an audience to be convinced by its realism and focus on the story … (that’s) what makes special effects so cool,” he said.

Hwang is the founder and CEO of Technical ART Studio CELL or “CELL,” South Korea’s leading special effects and makeup company, which he started in 2003.

He has worked on the special effects, props and makeup for hundreds of films and television shows. This includes many of South Korea’s most notable films, like the zombies of blockbusters “Train to Busan” and 2020 sequel “Peninsula,” as well as the props and makeup in Bong Joon-ho’s films “Okja” and Oscar-winner “Parasite.”

Striving for perfection

Hwang’s latest effects will appear in the next installment of Netflix’s popular South Korean zombie series “Kingdom” – a show he believes launched him and his CELL team to special effects fame. This special episode, airing July 23 and titled “Kingdom: Ashin of the North,” stars Jun Ji-hyun, one of the country’s best-known actors.

The series premiered in early 2019 and follows a historical narrative, mixing in elements of horror and politics. In it, a mysterious “resurrection” plant turns the people of Joseon-era (late 14th - early 20th century) Korea into zombies.

A scene from Kingdom's first season showing Korean period zombies.

Hwang and the CELL team have provided the special effects since the start and worked closely with the show’s creators to come up with a bespoke concept for a Korean period zombie. He factored many different elements into his creative thinking, including the zombies’ social statuses when they were alive. “Commoners would have farmed a lot, making their skin tanned,” Hwang said. “The king or court ladies who worked in the palace would see the sun less, making their skin lighter.”

He said his team tested many zombie looks and styles; many didn’t make the final cut. “There was a zombie that had died in the winter, so we painted the tip of the zombie’s nose and ears black to make it seem like they had frostbite,” said Hwang. “However … the zombie unintentionally looked rather comical instead of real.”

Hwang strives for perfection and for him, the beauty is in the details – from the blood around the zombies’ mouths, to the seeds of the resurrection plant stuck on their gums. “I remember we made fake teeth and the seeds and pasted each one on set,” Hwang recalled. “Whenever zombies opened their mouths big to attack people, you can see, if you look closely, the seeds. It might not have been so obvious on camera, but the director focused on every single detail of how the zombie looked.”

That level of detail means more time in the makeup room, especially for the zombies requiring more closeup shots. For example, a team of 10 people worked on the king’s makeup for around three hours every day. For more “average” zombies, requiring just the addition of wounds and rotting skin, it took the team about an hour.

Actor Jin Seon-kyu runs from a horde of zombies in season 2 of "Kingdom."

Across all the episodes of “Kingdom,” Hwang said that his team worked on around 3,000 zombies in total – 10 to 100 zombies on an average day for 150 shoot days. According to Hwang, they used the most effective, time-saving method they knew: an assembly line.

“Two or three people worked on the skin tone, while others were in charge of fake skin and wounds,” he explained. “Another team drew in the veins, while another added the blood and finished the look.” Throughout the production, he estimates he used more than one ton of fake blood.

Beyond the undead

Although audiences outside Asia may know his work from hit zombie movies “Train to Busan” and “Peninsula,” Hwang’s work extends beyond the undead. For nearly two decades, he’s created some of the most innovative visual effects in the South Korean film industry, using prosthetics, makeup, dummies, props and animatronics.

His team’s creativity isn’t always meant to be obvious on screen. For example, in “Parasite,” they created a peach from scratch, making the fruit fuzzier so it could be captured more easily on camera and to accentuate its symbolism in the film.

Hwang and his CELL special effects team created this peach from scratch for the Oscar winning film "Parasite."

For the 2008 film, “The Good, The Bad, The Weird,” Hwang said his team developed animatronic horses for the first time in South Korea. “It’s a moving horse without legs and actors look like they are riding,” he explains. “I feel proud that I was able to contribute to a safer filming environment by developing this.”

The Netflix horror series “Sweet Home” mixed CELL’s terrifying creations with CGI to create scenes of monsters wreaking havoc on the world. “We had to make creatures that we have never seen in Korea with (huge) tentacles,” said Hwang. “We wondered, ‘How can we do this? Don’t we need CGI for this?’ When we finally watched what we thought we couldn’t do … or found frustrating to do at first… we (felt) proud.”

CELL created the monsters featured in the webtoon turned post-apocalyptic horror series, "Sweet Home."

There’s pressure though, according to Hwang. As televisions get larger and resolutions get higher, for him, even the smallest mistakes become more obvious. He gives the example of attaching artificial skin: “If you can see the edge of it, then it shows that it’s fake and it will distract the audience,” he said. “We always carry the burden … to make it perfect.”

Realizing his dream

Hwang’s next project has his sights set on a new frontier: creating a realistic portrayal of life in outer space for upcoming Netflix original series “The Silent Sea.” With actor and director Jung Woo-sung as its executive producer, the space thriller stars Bae Doo-na, Gong Yoo and Lee Joon. For Hwang, it’s yet another new genre to tackle.

CELL is creating the space suits and equipment for the series "The Silent Sea," which tells the story of a team visiting a research base on the moon.

While Hwang once dreamed of working in Hollywood, he said that is no longer the case. Because his projects have now been watched globally – and by his special effects peers in other countries – he feels that his hard work and attention to detail has paid off.

“Now when I tell people that I was on the special effects makeup team for ‘Train to Busan’ and ‘Kingdom,’ I don’t feel the need to work for Hollywood movies to realize my dream anymore,” he said. “I feel rewarded.”

CNN interns Jae-hee Jung, So-hyun An and Anagha Subhash Nair contributed to this report.