Greenmist quest was broken until Chardok revamp, as Arteker said. It
was released with Shissar bane damage, generally considered a Luclin teaser. AFAIK the only change to Greenmist in Luclin+ era was that it was changed to be usable by all SK races; don't remember when that change happened but I'd think it wasn't too far into Luclin.
And Greenmist is one of the best "lore" items ever IMO, although I find it curious that while the Greenmist Khukri is either a symbol or fragment of, or perhaps once Rile's "remote control" for, the green mist that drove out the shissar, Trakanon's AE also seems to hint at a connection:
A green mist seeps into your skin. Poking around a bit... Sony
removed the "green mist" reference from the AE in August of 2003... I wonder why? I think that was LoY or LDoN era? Can't figure what the reason would be. Hmm...