Electro field

When you cast this spell a surge of electricity surges through your body going through to your hands. Then the electricity drops out of your hands and turns into      
4 little electro balls that move away from You in different directions   ,on the floor After 20ft away from you  they explode into a bigger balls and hit any creature in a 10ft radios of the ball as it grows. If any  creature gets hit each round inside the electro ball does 3d8 at 5-6th level 4d8 at 7-8th level

every level 1 ball is added to the field.