Rapier of Life Stealing

When you attack a creature with this magic weapon and roll a 20 on the d20 for the attack roll, that target takes an extra 15 Necrotic damage if it isn't a Construct or an Undead, and you gain Temporary Hit Points equal to the amount of Necrotic damage taken.

Vex (Mastery): If you hit a creature with this weapon and deal damage to the creature, you have Advantage on your next attack roll against that creature before the end of your next turn.

Finesse: When making an attack with a Finesse weapon, use your choice of your Strength or Dexterity modifier for the attack and damage rolls. You must use the same modifier for both rolls.

Proficiency: martial, rapier Source: Dungeon Master's Guide (2024) p. 314