If you don't want to paint. Get 2 large art canvas,s 4X4 or bigger..paint or stretch fabric over them and hang one above the other. It will bring drama into the room. Hang drapes as high as possible for more drama

https://www.houzz.com/magazine/tall-tales-ideas-for-two-story-great-rooms-stsetivw-vs~205220

I don't know where you live but you can pull up an amazing magazine called Phoenix Home and Garden which contains many ideas for 14/16 ft. ceiling treatments.

Consider shutters, but it really depends on what kind of space do you want this to function as for you. It makes me crazy when builders put a vent right in the middle of a huge wall. If this will be a room with a tv then you could have a entertainment area on that large wall.

I have the same problem. a tall wall. See my recent post fire1fly for more ideas