Augmentative Energy Field

You project a catalytic field of arcane energy that makes fire burn hotter, frost freeze colder, or acid more violently corrosive.  The field is a 25ft cube that your create within range, and you must choose which element the field is attuned to when you create it.  You can attune the field to one of the following damage types: acid, cold, fire, lightning, radiant, necrotic, or thunder damage.  Attacks, spells, and other effects that deal the same type of damage as the one to which the field is attuned all deal an additional 2d8 damage of that type to creatures within the field.  On your turn you may use a bonus action to move the field up to 30ft.  The field lasts as long as you maintain concentration on this spell and you remain within 60ft of the field.  

A Higher Levels:  When you cast this spell using a spell slot of 4th level or higher, the additional damage increases by 1d8 for each slot level above 3rd.