The mystical beast emitting a rainbow-colored glow was the light attribute Divine Beast, the Light Dragon. However, it was still in its juvenile stage and did not appear to be very powerful.
Isolde's voice then reached the ears of the Light Dragon, saying, "Wait a little longer. I know you sensed Charles and are eager to act."
For Isolde, it wouldn't be perfect if the secret realm ended like this. He still needed Charles to continue his performance, so that the Beast Masters from the Haunted Marsh could be further shaken.
The Light Dragon had far superior perception of light and dark attribute energy compared to other Beast Masters and mystical beasts. The ninth-level Beast Masters outside the secret realm couldn't detect the pure light attribute energy inside Charles, but when Charles left the maze, the Light Dragon had already sensed him.
