Aria of Perseverance

You bring a steady rhythm to the ears of a faltering ally, bolstering them with endurance.

Choose a willing creature in range. That creature may spend a hit die and gain temporary hit points equal to a roll of the die plus their constitution modifier. These temporary hit points last until the ally next takes damage or when this spell is cast again.

At Higher Levels. The spell allows the target to spend more hit die at higher levels: two hit die at 5th level, three at 11th level, and four at 17th level.