Charm of Mass Heroism

Found inside the Durst Mill millstone along with the Hag's contract.
The charm allows the wielder to give any number of creatures within 30 feet the benefit of a potion of heroism as an action. Once they do so, the charm vanishes from their person.

Potion of Heroism:
For 1 hour after drinking it, you gain 10 temporary hit points that last for 1 hour. For the same duration, you are under the effect of the bless spell (no concentration required). This blue potion bubbles and steams as if boiling.


Bless:
Whenever a target makes an attack roll or a saving throw before the spell ends, the target can roll a d4 and add the number rolled to the attack roll or saving throw.