Caedus had chosen to conceal himself using his Fallanassi techniques. So far as the combatants were concerned, he was no more than a shadow on the wall. He watched with fascination as the children (despite the fact one of them appeared to be as old as his own daughter) went at it, lashing out at each other with fire, air, and water.
Caedus studied them as they moved with intricacy, each series of movements creating a different type of attack. As they fought, he came to the realization that without those movements, they were unable to generate their elemental powers. So, if someone, like an enterprising Dark Lord of the Sith, were to reach out with the Force, and grab them, thus restraining their movements....