In the Earth Sorcerer fight in Bandit Cave, the enemies are level 47-49. This is about ten levels higher than the levels' of the other enemies, which are 37-39. Please lower the levels of the enemies in this fight, because some pirates playing at its intended level may not be able to win this fight.
It also may be that somehow you skipped a section of the game before you are supposed to fight the Earth Sorcerer in the Bandit Cave. Another reason might be that KI wants you to level up before you fight the Earth Sorcerer in the Bandit Cave.