As an action, shimmering energy surrounds and protects you from fey, undead, and creatures originating from beyond the Material Plane. For the duration, celestials, elementals, fey, fiends, and undead have disadvantage on attack rolls against you.
You can end the spell early by using either of the following special functions.
Break Enchantment. As your action, you touch a creature you can reach that is charmed, frightened, or possessed by a celestial, an elemental, a fey, a fiend, or an undead. The creature you touch is no longer charmed, frightened, or possessed by such creatures.
Dismissal. As your action, a celestial, an elemental, a fey, a fiend, or an undead within 18 meters must make a Will saving throw.
On a failed save, the creature is sent back to its home plane (if it isn’t there already). If they aren’t on their home plane, undead are sent to the Shadowfell, and fey are sent to the Feywild.