Zapping Lemon Hexmallow

Marshmallow Magic This marshmallow has It has a strong acidic flavor with only a hint of sweetness. It numbs your mouth slightly when you eat it.
  You can use a bonus action to eat this marshmallow, when you do, your abilities, attacks and spells ignore any resistance to Lightning damage a target may have until you finish a long rest. However, for the duration you also are vulnerable to Lightning damage. If you are resistant, you lose the resistance. If you are immune, you become resistant. For the duration, you cannot gain the benefits of any other hexmallow.