Bloodbane

It carries the bloody taint of an inhuman madman.

A blackened demon blade

Vorpal brand
Allows Berserk
Forces Berserk
-20 Stealth

Desirability

Very nice if you can nerf the berserkitis, but if you have to use an amulet of clarity to do so, you'll probably want to eventually switch to a normal demon blade: it is far preferable to have something like conservation or resist mutation in your amulet slot, and a well-enchanted demon blade of freezing will provide more damage output. Being undead or worshiping Ashenzari will give you a bit more leeway for using this weapon. Similar to but somewhat weaker than the Sword of Jihad.

History

Truly a shapeshifting weapon, first it was a long sword, then a katana, now a demon blade. In 0.9 this weapon was the only katana in the game.