The term "mkv" usually refers to a high-definition video file format. This suggests you might be looking for a digital copy of a film or series covering this story. While there isn't a single definitive modern blockbuster with this exact title, the legend of Phí Phan and the Tam Hiệp period is a popular subject in Vietnamese historical dramas and literature. The Legend of Phí Phan

Phí Phan is often portrayed as a strategist and warrior who stood against the territorial expansions of the Wu or Han empires, becoming a symbol of local defiance.

Many older Vietnamese dramas are archived here; you can use tools to save them in your preferred format.

or Galaxy Play: These platforms often host high-quality Vietnamese historical series and movies.