The Binding Blade
Melee Weapon (Simple, Dagger), Legendary, Requires Attunement
Damage: 1d4
Damage Type: Piercing
Properties: Finesse, Light, Thrown (range 20/60)
"An ancient bone blade of legend, carved from the bones of a celestial being. Having the power to bind the souls of even the most powerful beings, it has been used for great good and even greater evil. While the nature of the blade is neither good nor evil, the power it offers is often a corrupting influence on those who wield it. "
You gain a +1 to Attack and Damage rolls with this magical weapon. Additionally, attacks with this blade deal an additional 1d4 Radiant or Necrotic damage, chosen when the attack is made.
Soul Prison. Upon dealing a fatal blow with the blade to a living creature, the spell Soul Cage is immediately cast (ignoring the material component) upon the killed creature. The creature’s soul is immediately trapped within the blade and can be exploited per the Soul Cage spell. The spell automatically fails if the creature killed is a Beast, Construct, Ooze, Plant, or Undead. Creatures with an Intelligence of 3 or less are also immune to the effect.
Additionally, while ensouled, the blade’s Attack and Damage bonuses are increased to +2 and attacks with the blade deal both 1d4 Radiant and 1d4 Necrotic damage. When making an attack, you may exploit the soul trapped within the blade (per Soul Cage) to increase the Radiant and Necrotic damage to 2d4 each.