The crystal sword was a powerful artifact and weapon in the Tortallan Universe.
The sword was made by Duke Roger. Like all of the objects he created, the duke put some of his magic into the sword, thus its evil and immensely powerful nature. Although Alanna the Lioness managed to diminish the evil in the sword, she never managed to get it fully under her control. She only got full control over the sword after she combined it magically with her broken sword, Lightning.
The sword is described as having an odd crystal blade with a silver hilt. The hilt is slightly longer than Lightning’s, etched with occult symbols and studded at the pommel with sapphires and diamonds.  The designs are much like those on the wizard’s rod once held by Duke Roger.
Alanna of Trebond first encountered the sword when she traveled in the Great Southern Desert shortly after she received her knight’s shield. The arrows of the Bloody Hawk tribe felled the Hillman that wielded the blade when the tribe assisted Alanna and Coram Smythesson. Halef Seif, the headman of the Bloody Hawk tribe of the Bazhir, sensed the sword was evil in nature and had Alanna leave the sword to the desert. The shaman, Akhnan ibn Nazzir, however, went to get the sword the following night and was eventually consumed by the sword when he tried to kill Alanna and used his own live force up.
Alanna took control of the sword working to diminish the evil that had corrupted the magic the sword possessed. Alanna’s apprentice, Ishak wished to wield the sword but Alanna refused him. Then the night after an attack on the village by Hillmen and their shaman, Ishak took the sword from the sleeping Alanna and tried to wield it. When he took it out of the scabbard to shout a spell at Alanna, the shield she had summoned to protect herself reflected the spell back at him. The power consumed him and the scabbard he had thrown aside.
In the last fight between Alanna and Roger, he uses the magic he placed in the crystal sword to call it to him. With Lightning fused with the crystal sword, Alanna is able to hold onto the sword long enough to be able to use Roger’s own call to fling the combined swords into his chest, killing him.
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