From DivNull RPG
Tesharna is a long, thin sword, with a silver hand guard fashioned to resemble a bat with spread wings and a gaping mouth. It is telepathic and intelligent. It bonds with a user, and it gets stronger the more it “feeds”.
Tanador carried this blade for a very long time, but rarely actually killed anyone with it. He was, in truth, a bit afraid of it. When initially identified, it showed a very powerful magical aura, more so than any magic item Tanador had ever identified (9 on Jeff’s scale).
Tesharna once warned Tanador that using it to attack undead would be a very bad idea.