Elemental Master

When you gain this feat, choose one of the following damage types: acid, cold, fire, lightning, or thunder.

• You gain resistance against the chosen damage type. If you already have resistance, you instead have immunity against the chosen damage type instead. If you already have immunity or receive immunity after taking this feat, any damage you take of this type heals you by half of that damage.

• When you take any action that deals damage of the chosen type, you ignore a target's resistance to that damage type. If it is immune to the damage type, it is considered to have resistance instead of immunity (it takes half damage instead of none).

• You gain a cantrip and a 1st level spell that deal the chosen damage type. You can cast that spell once per long rest or using your spell slots.

You can only become a master of one element.