Just a note (in case you didn't know) on this guy since we killed him a few days ago for a LS member: 1) he has insane regen. Like INSANE. You need a lot of DD to be able to kill him. DoT spells help. 2) Melee DD will be better off 70+. His evasion is very high. The first time I fought him @70 ninja I had a hard time hitting even with sushi+Scorp Harness+Opti hat+Snipers. 3) The camp area is flanked by some Bombs on one side (magic aggro--extrememly long range) and a raptor on the other. If you have too many people you run the risk of aggroing one or the other, which just makes things more difficult and takes mage attention off Vouivre in order to sleep the adds.
All in all not too hard a fight. Vouivre doesn't do much aside from normal Wyvern special attacks, although his normal attacks are Double/Triple every time, but with a long delay in between. Just bear all this in mind, prepare accordingly, and the fight should go smoothly -_^