Fane-Eater

Fane-Eater is a battleaxe belonging to Arkhan the Cruel. You gain a +3 bonus to attack and damage rolls with Fane-Eater. If you attack a creature with this weapon and roll a 20 on the attack roll, the creature takes an extra 2d8 necrotic damage, and you regain a number of hit points equal to the necrotic damage taken.

Versatile: This weapon can be used with one or two hands. A damage value in parentheses appears with the property—the damage when the weapon is used with two hands to make a melee attack.

Proficiency: martial, battleaxe Source: Baldur's Gate: Descent Into Avernus p. 223