Vulnerability

You gesture to a creature you can see within range and break the glass in your hand, causing them to suffer magical susceptibility to harm. When you cast the spell, you choose bludgeoning, piercing, or slashing damage. Until the spell ends, the target has vulnerability to that type of damage, if they do not have resistance or immunity to that type of damage already.
If the creature has immunity to that damage type, they instead have resistance to the damage type for the spell's duration. If the creature has resistance to that damage type (or if they have resistance to nonmagical attacks from that damage type), they instead lose resistance to that damage type for the spell's duration.

Creature by Building Paper Mountains
Art by Artur Gurin