Blacksteel

One metal weapon you touch becomes matte-black and utterly silent for as long as the spell lasts and you have contact with it. The weapon makes no sound when drawn or when in contact with another object. The weapon deals an additional 1d4 necrotic damage and whenever you reduce a creature to 0 hit points, you gain 1 temporary hit point.

This spell's damage and temporary hit point gain increases by 1d4 and 1 when you reach 5th level (2d4/2), 11th level (3d4/3), and 17th level (4d4/4).