If your people are less happier than the Astari during a festival, you will lose some Followers to them (usually from the same settlement). To keep your citizens happy, use God Powers. Use the God Seed to plant trees just before an Astari festival is about to start, and just enough for your Followers to be above the Astari. Do not plant too much, as each seed costs progressively more. Use the Rain of Purity and Beautify similarly when they become available. You can also decrease Astari happiness, by using Meteor Showers, Swamps, and Fingers of God. You can also destroy them by removing layers from below them until they fall and drown in the water.