Corruption Blade

You coat your weapon in a powerful magic virus. When you strike an enemy, they must make a constitution saving throw. On a failed save, for the next minute, if one of their allies enters a 5 ft ring around them, both the victim and their ally take 1d8 acid damage. On a success, they take 2d4 acid damage immediately and suffer no other effects.

At Higher Levels: When cast using a spell slot of 3rd level or higher, the damage increases by 1d8 for each slot level above 1st.