I have a new LEGO set that I can't identify. I have looked all over Google. It came with a round glass door that looks like it could probably be a trap door and a plain black head and a grumpy face head. Also there is a black hood or helmet thing and a red one that cover the whole face but those are the only distinctive pieces. The whole set is mostly gray and black with a few red pieces.
As Phil mentioned, it's hard to give a definitive answer without a picture to help, but based on your description, it sounds like you may have at least part of Death Star Final Dual (75093):
This set is the only one I'm aware of that:
- Is mostly gray with a little red
- Includes a non-printed black minifig head
- Includes a black hood element
- Includes a red element that covers the entire face
- Includes large round transparent elements