Slahan was the sword forged by Nocker out of a shard of the Gate of Horn. It contains the soul of Lord Dougal.
After Lord Aelil used the weapon to kill Sidabras, it lay on the blasted plain until Rain took it and the two remaining bones of the dragon.
[What was Rain doing there? What did she do after taking the sword but before returning to Arcadia? Did she take Slahan back to Arcadia? What happened to it then?]
Slahan was the only weapon which could pierce Sidabras's hide, being made from one of his own horns (which had been shaped into the Gate of Horn.