Doombolt

Tendrils of shadowy energy reach out to envelope your target, surrounding it in a tangible fog of despair. Make a ranged spell attack against the target. On a hit, the target takes 4d6 necrotic damage, and the target has disadvantage on ability checks and saving throws until the start of your next turn. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for each slot level above 1st.