Can you help identify my new LEGO set? Round glass door, black and red hoods, 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