More specifically, the Hiltless are these shards that would go on to be wielded by great warriors who killed Old Beasts as they killed them in turn. The blades, natural conduits for magical energy, absorbed the immense powers of both warrior and creature. So brimming with energy were these blades that they threw off their fixtures, and to this day destroy any attempts to permanently bind or control them, hence their being named the Hiltless.
Because they are just blades, it is difficult to wield them without cutting oneself and activating the weapon's power with blood. The powers the blades grant are valuable - invulnerability being an example of one - but each comes with some curse to match the boon - such as one receiving all the wounds they inflicted on their enemies once they let go of the blade. Hence their second name, the Suicide Swords.
The Sword Seekers were a group who sought to collect and guard the Hiltless, though they faded into obscurity during the Silver Sickness in AM 147.
Currently wielded by Zazikel Heiros. When active, the weapon grants total invulnerability to the wielder, however all the injuries they inflicted on others are visited upon them simultaneously when they let go of the blade, or a day passes after it is first picked up.