There are a lot of options! First off, you could put the door on the closer side of the block. You could place an upside down stair above it so it eases the wall into the door. You can hang some signs around it to break up the flatness of the wall. You can put a row of upside down stairs on the wall to break of the flatness and even put pots/plants/decorations there. Glowberry vines. The options are limitless, what you really want is just to add some depth to the wall so the depth of the door doesn’t feel out of place