Gantoris is a human from the doomed volcanic colony of Eol Sha, one of the first students recruited to the Jedi praxeum on Yavin 4 in Jedi Search (Bantam, 1994). He arrives already convinced that a dark man will destroy him, which is the sort of prophecy Star Wars fiction never lets pass.
The spirit of the ancient Sith Lord Exar Kun, still bound to the Massassi temples the academy is housed in, works on him through his impatience and his fear for his people. He dies of it, burned from within, before the trilogy is halfway through. He is the first casualty of Luke Skywalker's decision to reopen a Jedi school on a Sith battlefield without asking what was buried there.
Catalogue entry. This figure has a verified record here rather than a full write-up — the encyclopedia labels its own depth instead of padding it.