Primordial Resistance

Starting at 1st level, when you take acid, cold, fire, lightning, poison or thunder damage, you can use a reaction to gain resistance to that damage type, including against the triggering damage, until the start of your next turn.

Elemental Impotence

Starting at 3rd level, you can hinder a creature's elemental abilities. When you hit a creature with an attack, you can choose one of the following damage types; acid, cold, fire, lightning, poison or thunder. The target creature must make a Wisdom saving throw or deal only half damage with the chosen type for the next minute or until you lose your concentration (as if you were concentrating on a spell). The DC for this saving throw is equal to 8 + your proficiency bonus + your Wisdom modifier.

You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.