Master of the Elements

In your arcane studies you have figured out wich part of an incantation determines the element of your spell.
Choosing this feat gives you the ability to switch the damage type of your spells.
To do so you need to spend a bonus action for a spell requiring an action to cast or an action for a spell requiring a bonus action to cast. 
Cantrips can be affected by this without spending any extra actions or bonus actions.

This feat can be chosen twice to give you additional damage types:
First: acid, poison, fire, ice, lightning, thunder
Second: necrotic, radiant, psychic, force