Vulnerability

Choose one creature within range. For the duration of the spell, the chosen creature has Vulnerability to one of the following damage types: Acid, Cold, Fire, Force, Lightning, Necrotic, Poison, Psychic, Radiant, or Thunder. (Your choice at the time you cast the spell) If the creature would normally be Immune to your chosen damage type, it instead becomes Resistant. If it would normally be Resistant, it instead takes the normal amount of damage. If the creature is already Vulnerable to your chosen damage type, the spell has no effect and automatically ends.