You must wait until the recruit is completely focused before killing the crab otherwise the mission will end in failure.
Wait for the message that says he is fighting with vigor.
Once defeated click on the Dawn Aureola to leave. All members will be rewarded 1103 EXP.
Return to Emhi Tchaoryo to complete the mission and receive 620 Allied Notes.
1-6 party members are required to participate in this Campaign Operation
Can be soloed at high levels or easily trioed at 75 by any jobs that can cure. DRG/WHM, BLM/SCH and WHM/BLM easily took this down. A tank is not needed since the Trained Crab will focus most of its attention on the recruit for the majority of the battle.
The crab will, however, occasionally attack members of the party who pull hate.
Protect and Regen cannot be cast on the recruit, but he can be cured.
During the battle the recruit will waiver in his focus. You must wait for him to regain his focus, try harder at his training and fight with vigor before killing the crab.