Arlus' Closed Circuit

“Electricity has lots of power, and we’ve only just scratched the surface of what it can accomplish. With the help of my god, we’ve figured out how to make it enhance the power of living things, and there’s only a very small chance that your heart will stop this time.”  - Arlus Licht, being asked about the spells he pioneered in an interview

Carefully passing current through the chunk of silicon, you choose up to 8 targets within range that are all within 20 feet of at least one other target, including yourself. These targets become linked with empowering arcs of electricity. Every target affected becomes vulnerable to Lightning damage; however, they make all damage rolls at advantage, have advantage on Constitution saving throws, and automatically deal maximum damage with Lightning or Thunder damage effects. If any of the affected targets go further than 20 feet away from another target, however, they lose these effects and cannot be affected by the spell again unless it is cast a second time. If your concentration on this spell is broken by force, every affected creature must make a Constitution saving throw or take 2d6 Lightning damage on a failed save, or none on a success. 

At Higher Levels: when you cast this spell using a spell slot of 4th level or higher, the distance the targets can be from each other increases by 5 feet per level above 3rd.