Metabot's Manual of Magical Maneuvers

Chromatic Blast

5-level Evocation

You gather up elemental energy in one of your hands and prepare to expel it into an enemy. Choose acid, cold, fire, lightning, poison, or thunder for the type of energy. You can use your spellcasting modifier for attack and damage rolls for unarmed strikes. The first time each turn you hit a creature with an unarmed strike, you deal 3d10 damage of the type you chose.
Additionally, you can choose to use your bonus action to transfer the enchantment onto the target, ending the spell. If the target is an Huge or smaller creature or object, it is pushed up to 30 feet away from you in a straight line (you choose). A glowing rune is left in the crater of your attack.   At the end of your turn, each creature within 20 feet of the target's location must make a Dexterity saving throw or take 6d10 damage of the type you chose. The target has disadvantage on the saving throw.