Fellblade
From Warhammer - The Old World - Lexicanum
The Fellblade is a magic weapon especially made for the destruction of Nagash by the Council of Thirteen, ruling body of the Skaven. Made from a special alloy of Warpstone and stolen Gromril, its power is so great that even its wielder will succumb to its deadly effects.
The first - and only known - wielder of the Fellblade was King Alcadizaar, last human survivor of the ancient realm of Nehekara.
Alcadizaar managed to kill Nagash but, maddened by what he had endured and suffered, he wandered away till he died. Nagash was eventually able to return but had lost a great amount of his power.
