Warp Bolt (Contaminated)

When you cast this spell, you gain one level of contamination. An arcing bolt of octarine lightning strikes a creature within range. If the target has one or more contamination levels, it is hit automatically. Otherwise, make a ranged spell attack against that creature. On a hit, the target takes 6d6 necrotic damage and gains one level of contamination.

You can create a new bolt of lightning as your action on any turn until the spell ends. 

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, you can target 1 additional creature for each spell level above 2nd.

*Credit to Monty Martin and Kelly McLaughlin via Dungeons of Drakkenheim