Its not fixing him if he stays paralyzed. Keeping the paralysis as an inconvenience/hinderance to his daily life keeps the thematic impact of his injury and offers opportunities to showcase him dealing with it. But Etheirys is a place with aether and magiteck and engineering geniuses in both fields. It kind of breaks your suspension of disbelief if they *can't* come up with a workaround to let him participate in combat again.

If he wants to, that is. Which might be the deciding factor. If Arenvald is content as a diplomat now, then he doesn't need a magiteck exoskeleton, even if one could be designed.