Originally posted by Unbowed
Luke still has no way of dealing with Kun's sorcery. If Kun's weakened spirit was able to dominate post-DE Luke, I'd say prime Kun should be able to do the same to Luke here.
1. JA -> FotJ Luke may very well be a greater increase than nexus spirit -> full body Kun. Seeing as how Luke has one of the highest ceilings of any character in the mythos, and as of JA he's only gotten to a fraction of it, I do think that descendant-of-the-chosen-one potential outstrips the difference between Kun's spirit and his body, seeing as how it's never implied that Kun is near that level of potential.
2. Exar Kun held various tactical advantages over Luke; he attacked him from the sides and behind while Luke, who didn't even know that Kun existed, was focused on Kyp, and he was incorporeal so Luke couldn't easily engage with him.
3. Luke at that point in time had virtually no knowledge of sorcery; by FotJ, we know that he's studied various aspects of the Force intensively, including presumably Palpatine's works that he acquired, and seemed pretty familiar with various trivia about the workings of nexuses, products of sith sorcery, etc.
4. Here, Luke can actually strike back against Kun, and using a level of power far beyond anything Kun has demonstrated or encountered, both through feats and accolades.