Minecraft wiki entry for Development_versions, associated text: Changed the maximum Bad Omen level for a maximum-strength raid to 5.
Kill leaders to increase Bad Omen level.
There are now two waves per Bad Omen level.
The player now has to complete a wave before the next one starts.
Illager beasts can now be part of every wave.
The raid boss bar will now slowly fill up when a raid is triggered or when a wave is cleared.