zelretch sword
One of Zelretch's Mystic codes and his main weapon. Commonly referred to as the "Jeweled Sword Zelretch" it's a jagged ceremonial ritual dagger with jewels encrusted in its hilt. The sword allows the user to channel into the blade potentially infinite magical energy which can then be fired off in a blinding stream of light.
Zelretch carries the original, and he has left blueprints of the sword with the Tohsaka family as a sort of long-term homework that he expects will take many generations. During Heaven's Feel, the sword is created by using these blueprints and other plot devices and Tohsaka Rin brandishes it to fight Matou Sakura in the climax of the route. The sword created is inferior to the original, and using it causes Rin's muscles to be damaged.