SEOUL (Korea Herald/Asia News Network) - K-dramas have notoriously favoured near-perfect male leads - attractive, intelligent heirs to vast fortunes and more.

Goblin, the show that has boasted record-breaking viewership since its premiere last month on South Korean cable channel tvN, has gone one step further, conjuring a knight in shining armour who is literally a god, television critics say.

"We've evolved past god-like men to actual gods, who have the appearance of good-looking men," said culture critic Jung Duk Hyun. "Now, their abilities surpass the realm of human strength."

Hit dramas in recent years have seen a surge in male leads who possess supernatural powers. In 2013's I Hear Your Voice, the male protagonist can read people's minds. The following year, My Love From The Star featured an extraterrestrial with superhuman powers of sight, hearing and speed as its romantic lead. In last year's Another Miss Oh, the male love interest is able to see the future.

Based on Korean folklore about dokkaebi, a higher spiritual being who is roughly equivalent to a goblin, Goblin stars Gong Yoo as Kim Shin, a warrior who was impaled on a sword centuries ago and transformed into an immortal with endless wealth.

Jung says the popularity of the character - Goblin has scored ratings as high as 12.7 per cent, according to Nielsen Korea - can be attributed to female viewers' yearning for all-powerful male figures who can solve the problems of modern women with increasingly stressful lives.

"The realistic ideal is that two people complement each other in a relationship," said Choi Ji Sun, 28, a lawyer who has watched every episode of the show.

"But it's easy to escape to a world where someone will come to my side at the drop of a hat, no questions asked, and provide everything. Of course, I would never expect that of my real-life partner."

In Goblin, the female lead Ji Eun Tak, played by Kim Go Eun, is able to summon Kim Shin simply by blowing out a flame.

Moreover, she is motherless, living with relatives who scorn her, and ostracised by schoolmates; Kim Shin comes to provide for and shelter her. Granted, she is lively and determined to survive despite hardships, seeking part-time jobs to support herself.

"But it's a shame she is unable to escape the Cinderella stereotype, especially when her male partner is so almighty," says drama critic Kim Sun Young.

Sparking further controversy, Ji is portrayed as a high school student and Kim is said to be 939 years old, though he has the appearance of a 30something man.

"The system of fantasy blocks any guilt and allows viewers to accept, without being repulsed, the romance between a minor and an older man," wrote TV critic Hwang Jin Mi last month. "But the image of a young girl...hanging onto a rich, 30something man...lingers."

Another issue that has plagued Goblin is its overt product placement. In a segment in its eighth episode, which aired on Dec 24, the two main characters are at Subway, discussing in detail which ingredients to choose and how large the sandwiches are.

The immortal and his housemate eat fried chicken from a certain franchise for days in a row; every piece of clothing and interior decor is exhibited as if in a magazine spread, and the camera captures brand names.

Though it is normal for dramas to use product placement to fund production, viewers say they have become "excessive to the point of distracting" in Golbin.

The products are "moving the plot along", said viewer Park Su Jeong.

The competition for product placement in hit dramas is higher than ever, advertising executives say, as featured items sell out instantly both in South Korea and throughout Asia. Makeup brand Laneige, for example, reaped 1.2 billion won (S$1.45 million) in profit from the lipstick used by actress Song Hye Kyo in Descendants Of The Sun.

Ads are meticulously timed and spread through multiple channels, said an entertainment industry source.

"After viewers watch the show, they go online to look up items they liked," said the source. "So bloggers are paid to upload posts featuring an advertised jacket, for example, right after an episode has finished. The brand then spreads to offline ads."

A spot on Gangneung's Jumunjin Beach has become a bustling tourist zone after Guardian shot a scene there. Recent social media photos showed lines of visitors waiting to pose for photos. Merchants have set up shop nearby with signposts that read, "Muffler, flower and umbrella can be rented for 1,000 won", allowing visitors to recreate the scene from the show.