Talos' Lightning Surge

Electricity is conjured and coalesces around a target so heavily that it and everyone around it can't possibly move without electrocuting itself or everyone around it. Choose an initial target that can be a creature or an object made of metal that's not being worn or carried. An electric charge builds within this target, who must make a Constitution saving throw. Creatures that are wearing or carrying metal make this save at disadvantage. On a failed save, the target takes 6d10 lightning damage and is stunned if the target is a creature. On a successful save, the target takes half damage and the spell ends.

For the duration of this spell, bolts of electricity arc out from the target in a 10ft radius. Creatures that enter the area for the first time on a turn or start their turn in the area must make a Constitution saving throw. Creatures that are wearing or carrying metal make this save at disadvantage. These targets take 6d10 lightning damage on a failed save, or half as much on a successful one. A creature can only be targeted by the arcing bolts once per round.

Metal that is either directly targeted or targeting by an arcing bolt heat up from the massive electric current and starts to melt. Deal an extra 1d10 fire damage to the metal, and anything touching the metal. This fire damage can only be applied to a creature or object once per round. If metal is the initial target of the spell and the fire damage destroys the item, the spell ends.

If the initial target of this spell is a creature, this spell continues until either the initial target passes a Constitution saving throw at the end of its turn, the creature dies, or until the spell is released. 

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, all targets take an additional 1d10 lightning damage, and the arcing range of the electricity increases by 5ft.