El Nath Party Quest

This party quest unlike the others require a level 120 warrior as a party leader to start this quest.

The 4th job warrior must be attempting to complete his Stance Quest.

Hunt for "Crimson Balrog's Plan" storybook from a Crimson Balrog, then talk to your 4th job instructor.
Now talk to Spiruna found in Cloud Park in Orbis. Give her the "Crimson Balrog's Plan".
Talk to your fourth job instructor. He will instruct you to find a "Bluish paper" that drops from Lycanthropes.
Once you acquire the Blue Paper, talk to your fourth job instructor again.
Venture to El Nath and talk to your 3rd job instructor. He will give you another quest to find a Gold Medal.
Enter the El Nath PQ and complete it successfully to obtain the Gold Medal.
Return to your fourth job instructor, and he will trade you a skillbook for Stance for your Gold Medal.
It involves protecting Tylus from monsters to obtain 4th job skillbooks.

The mobs that spawn in this map are Crimson Balrog, Lycanthrope and Werewolf.

Each mob has a chance of dropping the lvl 10 storybooks for Dragon Pulse, Showdown, Infinity. They drop frequently.

You need to either continually kill all mobs. Preferably with a party composition consisting of at least 2 archmages/bishops with their Blizzard/Meteo/Genesis.

The alternative solution is to lure all mobs to one side of the map (extreme right portal). that way no mobs will be touching tylus at all. (thus a solo warrior can do this with sufficient potions)

You need to maintain this until the timer reaches around 3 minutes left, then exit by the bottom right portal.

This will complete the quest for the 4th job warrior. He will not be able to start another El Nath PQ henceforth.

http://strategywiki.org/wiki/MapleStory/Quests/Party_Quests