Feifei’s Army of Monster Geckos

Every time the Cloud Whale passed overhead, Feifei became happy. She gradually noticed that Krune's mental state had recovered over the days as she sent him messages by engraving them on the ground.

On top of that, she determined Krune's cycle, creating a message on the ground only a couple of minutes before he arrived, erasing it soon after the Cloud Whale passed by. This way, she ensured none of the demons saw her messages. 

She also took measures to engrave the messages only in places where no demon ever appeared. By sending scouts to follow the line of demons marching forth in the valley nonstop, she determined that their destination was a human city.