Element Adept

Choose an element, Fire, Cold, Lightning, Acid, or Poison. Whenever you cast a spell that deals the chosen damage, you add one extra damage dice to the roll and enemies have disadvantage against the saving throw.

Alternately, if a spell you cast involves your chosen element and has a saving throw, and doesn't deal damage, the creature you cast it against still has disadvantage on the save.

You must have the ability to cast spells in order to take this feat.