Demon Bolt

Make a Ranged spell attack against a creature that you can see within range. On a hit, that creatures suffers 6d8 points of Necrotic damage. The spell's damage is doubled if you have Summon Lesser or Greater Demon active. 

For each level of spell slots used to cast this spell beyond 3rd, increase the damage by 1d8. Additionally, if you cast this spell at 7th level or higher, you heal for half of the damage dealt, rounded up.