An orion is a metal throwing star invented beyond the seas that has been used by Nilfgaardian Military Intelligence since 1266. They are small and easy to conceal, but accurate and lethal from up to thirty feet away. When thrown, they also make a whistling noise which is said to paralyze potential targets with fear.
Codringher took a liking to the weapon when he got ahold of some and practiced with them for a while. They were also a weapon of choice for Stefan Skellen, who ended up using one to mark Ciri's face.