Item from Memory, Sorrow, and Thorn by Tad Williams
The sky-sword — forged by the Niskies from a fallen star using the Words of Making, its hilt shaped like the holy Execution Tree, and cursed with a will of its own that compels whoever wields it.
Thorn was forged by the Niskies — sea-folk cousins of the Dwarrows — using the Words of Making, the same forbidden magic Ineluki used to create Sorrow. Its origin ties it to the Aedonite faith's holiest event, which makes it simultaneously sacred and terrifying. The sword has a will. This isn't metaphor — Thorn literally overcomes its wielders, compelling them to fight even against their own intentions. When Pryrates' ritual needed a swordsman, Thorn forced Camaris to participate despite his desperate resistance. The greatest knight in the world, reduced to a puppet of his own weapon. Camaris first took up Thorn at fifteen and became the most famous warrior in Osten Ard. Simon recovered it from the north, fighting the ice-dragon Igjarjuk in the process (earning his white hair-streak and the name Snowlock). After the climax at Green Angel Tower, Camaris and Thorn fell from the tower together and both disappeared.
A sword forged from a sky-stone — a meteorite that fell after Usires Aedon hung on the Execution Tree for nine days. The hilt is fashioned into the shape of that tree. The blade has an otherworldly quality — not quite metal, not quite stone, catching light in ways that suggest its material isn't entirely of this world.
Also known as: Thorn