I can't speak from experience, but I think Yuin Starchaser in Southern Felwithe might not be a classic NPC, most likely added in Luclin. He's associated with the Art Keeper's armor quests, which were added in Luclin. He may have existed before, but I couldn't find any record of it.
Here is some more research:
Google search from that era pulls nothing legitimate:
https://www.google.com/search?q=%22y...F1%2F2001&tbm=
First comment on alla is from Aug 02:
http://everquest.allakhazam.com/db/npc.html?id=9310
Only mention in alt.games.everquest is from Nov 02 for a PoP-era quest:
https://groups.google.com/forum/#!se...everquest/yuin
Missing in ShowEQ:
http://web.archive.org/web/200211210..._Felwithe.html
Missing in Illia's (Velious era):
http://web.archive.org/web/200111252....shtml?zone=55