My father, my grandfather and my grandmother were all "Vietnamese" in their previous lives, and only my mother was from Hubei. So am I a China-Vietnamese hybrid? I'm half-blood.

Actually, I don't quite understand what you said ...

If your father, grandfather and grandmother immigrated from China to live in Vietnam, then they are China people from Vietnam, and you are not a half-breed.

If your father, grandfather and grandmother are all Vietnamese (by blood), then you are half-blood, half-blood.