A protester Julia Hollingsworth/CNN

Hong Kong artist Kacey Wong is dressed for protest -- wearing black all over, carrying a black flag, donning a face mask and with a GoPro camera strapped to his chest in case police get violent.

Wong and thousands of other pro-democracy protesters are gathering in Admiralty, occupying the streets outside the government and police headquarters.

“This is a war. A war on culture, to be specific. If we win, our prize is very humble -- we get to keep our language, our way of life. If we lose, then the price is heavy," Wong said.

The black flag, an altered version of the Hong Kong flag, represents freedom and death, Wong said. He notes that the territory has only ever had flags chosen by Britain or China.

“The extradition law is seen as something that is only happening to Hong Kong,” he says. “But if you look more deeply, it will actually affect every nation on planet Earth. Any other nations’ citizens can be abducted back to China.”

Over the last month, critics have argued that the extradition bill could be used to send anyone on Hong Kong soil to mainland China for political or inadvertent business offences -- and encroach upon the city's rule of law and political freedoms.

What’s happening in Hong Kong is a “threat to the civilization of the free world," Wong said. “Hong Kong is just the first wave.”