Allegory's Arcing Witch Bolt

Allegory Jackson was a storm sorcerer who went on to achieve many great things, including the creation of his own line of signature spells using his vast well of tempest magic. Allegory's Arcing Witch Bolt allows the caster to target two creatures they can see within range, making a ranged spell attack against both. If only one attack hits, that creature takes 4d12 lightning damage as the other projectiles arcs to them, the spell ends on this effect. If both attacks hit, each creature takes 2d12 lightning damage, and an arc of electricity forms between them. Each subsequent round, at the start of your turn the creatures affected by this arc take 2d12 lightning damage. This arc can be broken by any nonmetal solid surface more than 2 feet thick in diameter.