Thunderous Cascade

A bright streak flashes from your palms, as a coalesced orb of crackling raw energy forms. Pushing it forward, a beam is unleashed at your target location, which bursts into a sphere of Wind and Lightning. 

The spell takes a Chant at the top of your lungs, From the power flowing out all at once, making silent concentration rather difficult. Thus, you require a decent amount of space, lest you accidentally shock an ally. 
You also need to see your target.

Each Creature within a 10-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 2d6 Lightning damage on a failed save, or half as much damage on a successful one. It does not round corners.

The spell's Damage scales with spell slot level and further increased, by feeding more spell levels into the spell. The scale is by 1d6. But going by spell levels, so 1(2d6)+1(1d6)=3d6
While 1(2d6)+2(2d6=4d6
The number of spell slots available to use at once depends on the caster level. 
Caster level 5= max number of useable slots is 5

The spell's base level determines Spell level and range and increases by increments of 10ft. 
When cast at 7th level or higher, the range distance can be selected as 'Within Sight'

Casting this spell puts strain on your body. Once the spell is finished, make a CON save against your own spell save DC. On a fail, you fall prone and loose the rest of your movement speed for that turn.