Unknown Japanese movie is haunting me for life.

[x909x]

I have this asian movie haunting me for my whole life.
I have no idea about the title. I believe it is Japanese, as it looked pretty elaborate.

I was the early 80s when I saw it, on VHS, around the time Indiana Jones: Temple of Doom was also out on video, so you get a clue when this might be released. Could be an earlier production of course but chances are that I picked it from new releases. I was a 7 year old kid back then and it definitely made a very solid impression, along with occasional nightmares.

Anyway, I have some distinctive images stuck in my head, but cannot seem to find any relevant info around the web or this forum:
- A devious woman (mistress?) taking a bath naked (milky white body) in a huge bath tub filled with blood. She was the evil character and had ordered many other people's death.
- Creatures like large centipedes moving fast in walls.
- Samurai action. Lots of arms/heads cut off.
- Dark, foggy atmosphere.

I know that might be not much to identify a movie (especially the latter two), but please can someone help me? I wanna see it again!

Thank you.