Elemental Surge

This feat is created by Nedrapter for use in his Land of Arda campaigns, and are balanced to the hardcore nature of them. 

• Whenever you cast a spell of 1st level or higher that deals acid, cold, fire, lightning, or thunder damage, a swirling aura of that element forms around you in a 10 foot radius, until the start of your next turn. Enemies that enter or start their turn in the aura take damage of the type chose equal to two times the spell's level.