In a well-decorated music studio, its walls adorned with posters of Ne Zha 2, China's highest-grossing blockbuster, two ultrawide monitors sit atop a large desk.

It's here that Tang Hanxiao, an experienced singer and composer, wrote the theme song for the film, re-recording the lyrics more than 600 times to achieve the final version.

Since its domestic debut on Jan 29, the first day of Spring Festival, the film — loosely inspired by the Ming Dynasty (1368-1644) novel Fengshen Yanyi (Investiture of the Gods) — has quickly shattered box office records, becoming the fifth highest-grossing movie in global cinema history.

Born to an unfair fate, Nezha is destined to die at the age of 3 as a result of a heavenly punishment caused by a curse.

However, with the help of his close friend Ao Bing — the son of a dragon king who guards thousands of imprisoned monsters in the roaring sea — he bravely defies his doom.

The premise, established in the 2019 blockbuster Ne Zha, which earned 5.035 billion yuan ($695.4 million) in ticket sales, sets the stage for the new film, which begins with the resurrection of Nezha and Ao Bing, whose bodies were destroyed at the end of the first movie, while their souls drift.

In the summer of 2024, Tang was asked to compose the music and co-write the lyrics.

As Ne Zha 2 was then still in post-production, he was given only the plot and allowed to watch the last two minutes of the film, where the free-spirited hero, having just emerged from a fierce battle to rescue his loved ones and defeat the villain, tells Ao Bing that he has decided to continue his fight against the corrupt order.

"This scene gave me a vision of the entire film and allowed me to feel the energy embedded in the line. Everything about the song begins with this scene," says Tang.

For Tang, the creation process of Jiushi Nezha (It is Nezha), the song for the character, was a deeply personal journey — one that used music to connect with and reflect the unique personalities of the roles.

The composer says the suona, an instrument known for its stirring and powerful sound, symbolizes the courage to challenge society bias, making it a perfect match for Nezha's bold and rebellious nature. As a result, it became the driving force behind the song.