The Deadly Phantom Faceoff - S1.E12

The surviving criminals threaten the villagers in order to be handed over the treasure. Ryu and Ken accept to enter the cave to save the villagers' lives. Once inside, the two boys hallucinate over the cave's mist and start to fight each other, thinking they're both fighting the "cave's monster". After almost killing themselves in the fight, they realize the hallucination and get the treasure to the criminals, only to be threatened to be killed together with the villagers. Dhalsim paralyzes the two criminals and then heals Ryu and Ken's injuries, accepting to teach the boys the ways of Hadou.