I saw this move in the early 90s but it looked older, most likely 80s but maybe 70s.

The movie is developed in a funerary house, or at least part of it, on the ground level the house is like a regular funerary house with a small chapel-like room, and the basement is where the bodies are “prepared” for the funeral. The “bad guy” is a tall pale man who wears a suit, and I’m pretty sure he wears a hat too. On the last scene, the bad guy, who apparently survived to the usual horror movie drama is seen walking on the funerary house hallway until he reaches a body on an open coffin, he then grabs a syringe and pinch the body extracting (or maybe introducing) some sort of white-yellow-ish translucent liquid to the dead body. We can then see that after removing the syringe from the body, the bad guy licks a drop of the liquid that was dripping from the needle of the syringe. I cant remember well, but I’m pretty sure that the liquid played an important role in the movie.