In The Legend of Mir, warriors and sorcerers battle creatures from an ancient universe. Now, WeMade Co.'s longtime video game hit is at the center of a string of legal battles that could serve as a rallying cry for foreign companies harboring grievances against Chinese rivals.

Over the last three years, the South Korean studio's chief executive officer, Henry Chang, has filed about 65 lawsuits in China, Singapore and South Korea against Chinese gaming studios, attempting to block what he alleges are unlicensed versions of his two-decade-old title.

That makes the 44-year-old one of the few foreign executives audacious enough to challenge a batch of Chinese firms in the world's largest video game market.