The Sacrificial Blade

Weapon (several types), rare (requires attunement)
A wooden blade imbued by sacrificial rites. The blade is hard but surprisingly light. The hilt fits very nicely in the hand and has ornate silver filigree. A sphere of onyx is gripped in the pommel.
You gain a +1 bonus to attack and damage rolls made with this magical weapon. Reducing a creature to 0 hit points with an attack from this weapon grants you half your level (minimum of one) of temporary hit points.
Featherweight blade: This weapon has the Light property, unless it has the Two-handed or Versatile property. It also does not have the Heavy property.
The weapon has 5 charges. Once per turn when you hit an enemy with it, you can expend a charge to deal an extra weapon die Necrotic damage as part of the attack. The weapon regains all charges when you finish a long rest.
| Weapon type | Damage | Properties |
|---|---|---|
| Dagger | 1d4 piercing | Light, Finesse, Thrown (range 20/60) |
| Scimitar | 1d6 slashing | Light, Finesse |
| Shortsword | 1d6 piercing | Light, Finesse |
| Rapier | 1d8 piercing | Light, Finesse |
| Longsword | 1d8 slashing | Versatile (1d10) |
| Greatsword | 2d6 slashing | Two-handed |
| Double Bladed Scimitar | 2d4 slashing | Two-handed, Special |