This is a capped level 40, three-person, battle against Carrion Dragon. This battle is easily soloed by most jobs 35+ (see testimonials).
This battle event is not repeatable. If you are trying to help a friend out, and have already done the quest, you will not be able to re-enter the battlefield unless you've started over with Luto. You cannot enter the battlefield unless the quest is active, even if you have not yet completed this battlefield.
Buffs will be erased upon entering the battlefield. You will also lose all TP. However, the dragon does not attack at the beginning of the battle, giving you time to buff up.
The battle will last until the dragon is at approximately 80% of its HP. At this point, another cutscene will play in which your friend appears. After this cutscene, all party members' friends will appear, and aid in downing the dragon.
Trust magic is not allowed in this battle.
Head back to Luto Mewrilah after the dragon battle to finish the quest and receive your Signal Pearl.