The Grim

Description
"He inspected the weapon the girl had given him and smiled grimly. Whatever else she might be, she was proven by that dagger to be a person of practical intelligence. It was no slender stiletto, selected because of a jeweled hilt or gold guard, fitted only for dainty murder in milady's boudoir; it was a forthright poniard, a warrior's weapon, broad-bladed, fifteen inches in length, tapering to a diamond-sharp point."

- The Hour of the Dragon

About twenty years ago, a murderer stalked the streets of Belverus, the capital of Nemedia. Every night, young men and women would go missing from the streets, and their corpses would be found later, mutilated and laid at the doorsteps of their homes.

The people cried out for the murderer to be captured and the watchmen found a suspect, a middle-aged lamplighter who was captured with two blood-stained poniards during his rounds one night.

For his part, the lamplighter told an unbelievable story. He claimed to have seen the poniards floating through the air of their own accord. He said that when he moved towards them, they turned and flew at his throat. Ducking aside, he turned to find that they had embedded themselves in the sideboard of his cart.

Despite this wild story, he was hanged for his crimes. The murders ceased. And the city slept. And the poniards were never seen again.

These poniards, when used in battle, will increase the damage of every strike.

Source
The  can be found in Legendary Chests, or can be dropped by shaleback bosses.

Repair
This item can be repaired with a.