So they can fall off the edge and die if they fall to far. It can only happen when approaching them with the opposite energy type as their aggressive state for the dark guys and the flee state for the good guys stops checking for the ground. I was think that could be used for a puzzle but did not get that far. I am guessing you approached him with a light charge while he was near the edge. That or he bugged and missed the physics check for the ground. Thanks for playing it.