A nutcase thinks that his weapons need to be fed.
Needs a Better Title, A Better Description, More Examples, and An Index. Seen It a Million Times. Do We Have This? Rolling Updates.
There are many ways to tell if an unknown warrior is bad news. He may have Spikes of Villainy, evil-looking scars, or carry gruesome trophies around. But the absolute worst sign of them all, is when he declares that My Sword Is Thirsty. This trope instantly identifies the character as being Ax-Crazy, a Blood Knight, or otherwise dangerously crazy. He almost certainly kills just For the Evulz, and generally doesn't even try to channel it. He might even be an Omnicidal Maniac. A form of I Call It Vera in that the wielder anthropomophizes the weapon, to the point of believing that it has desires of its own. Not to be confused with an actual Hungry Sword, although those are generally a bad sign too.
Examples:Anime & Manga