Shaolin Mantis(1978)

Now that he learned the secret... he was ready to kill!

When scholar Wei Fung is forcibly hired by the Manchu Emperor to infiltrate a clan of rebellious Ming Loyalists, his mission goes adrift when he falls in love with the clan's leader's granddaughter. Wei Fung must choose between his new love and his family, who will be put to death if he doesn't return to the palace successfully.