Blade of the Blood Chief

This is a +1 weapon that amplifies the Feast of
Blood ability of vampires, once during each
combat, when you kill a living creature, you
instanly trigger the Feast of Blood ability.
Special. When you take the attack action and make
a two-handed attack with a double-bladed scimitar,
you can use a bonus action to make a melee attack
with the blade at the opposite end of the weapon.
The weapon’s damage die for this attack is a d4,
and it deals slashing damage.