Fireplace Design Help

Just design it like the one in the great hall of Hogwarts

Is it possible to add sheetrock(wall) to the left side(stairs) to make it symmetrical. Basically full in the upper left with wall. Then fill in the TV hole, stud and sheetrock. From there I would add another set of built in shelves to the right of the existing. Add a mantel above the fireplace. The fill in of the wall and built ins will help it not look as "off" as it is now

Start over dang. I'd frame in the left side near the stairs so that's not offset. The cubby for the TV needs to go, and the cabinet as well.

Doing all of that I would just frame it in, and move the fireplace and literally start over.

If you reconfigure the lower cubby (with height matching the top of the fireplace) into one for stacked firewood and made a second, matching firewood cubby to the right of the first, and placed a chunky (or not) mantel across the firebox and both of the cubbies, you could balance the look. And of course, delete the other, higher one.

Is it a ventless fireplace?

Personally, I'd remove all the drywall to the right and move that wall back to even with the back of the cubbies and TV recess.