Once a year, one of the [[Exarch]]s of a Craftworld is chosen to hold the title of [[Young King]]. When a Craftworld prepares for a major war, its Exarchs begin to feel the Avatar's call. All Exarchs go to the door leading into the Avatar's chamber. There they begin the ancient ritual to rouse the Avatar, where they anoint the Young King and sing battle hymns. Then the chamber's door opens, and the Young King enters.

The Exarchs continue the ritual at the entrance. It may take hours or days, but finally a terrible scream echoes from the chamber and the Avatar rises. There is no sign of the Young King - it is assumed that the Avatar absorbs him and his memories of battle, thus becoming more powerful and skilled.