The control stone [1] is a small, ornately carved sphere, in the shape of an egg. It is used to control Ohma, the God Warrior.
The control stone first appears in the story when the mortally-wounded Rastel (Lastelle) gives it to Nausicaä after the crash of the Pejitei Brig [2] with the request to give it to her elder brother and the admonishment that the Vai Emperor should never get it.
Nausicaä takes the stone and returns to the Valley of the Wind with it [3]. Kushana finds the crashed Pejitei Brig with a troop of Worm Handlers and tracks the stone to the Valley [4]. After a confrontation with Nausicaä, she is convinced that the stone is being held by Nausicaä and uses the Periphery Campaign to try to get it[5].
Nausicaä rescues Asbel after his attack on the Periphery Campaign Forces and gives him the stone[6].
References[]
a See Page Conversions Between Editions to convert Deluxe Edition volume 1 (DE1) to other editions