Evergreen Acorn is a Keepsake that allows Zagreus to take a certain number of hits from a Boss without taking any damage. It is obtained by giving Eurydice a gift of Nectar while visiting her sanctuary in Asphodel. Its effects can be enhanced by clearing enough encounters with the keepsake equipped.
Unequipping the Evergreen Acorn between levels will remove the damage nullification Zagreus receives from the item.
in the final encounter in each underworld region, take 0 damage the first 3/4/5 times foes hit you.
From Eurydice; you share an Inspiring Bond
Singing for the joy of it, she lives for the moment, even in death.