Darth Vader ring, built to show the world your allegiance to the Federation!
There are two ways you could print this ring, the first being the simple use of support. For a cleaner top surface, though, I would recommend using the "Pause at height" plugin of your favorite slicer at .75 mm or whatever your layer height is that begins printing the flat top of Darth's helmet. After the printhead has moved away from the object, place a couple of stacks of tape layers (.75 mm thick) along the top fin of his helmet. This will give the helmet a much easier to remove support.
Ring base is from the Saw Ring by Bre, ring top is from his Darth Vader helmet.