Voltaic Spike

Channelling electrical energy between your fingers, you make a melee spell attack against a creature within your reach. On a hit, the target takes 3d8 lightning damage and has disadvantage on the first attack roll it makes before the end of it's next turn.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.