Acid Lash

You magically coat a melee weapon you are touching in fuming acid that hisses and bubbles. The next time the affected weapon strikes a target within this spell's duration, it inflicts acid damage equal to 2d6 plus your casting ability modifier and afflicts the target with an acid lash, a line of acid across their body, for 2 rounds. Once the lash is applied, the spell's primary effect ends.

While afflicted with the lash, the target suffers disadvantage on all dexterity saving throws, disadvantage on constitution saving throws made to maintain concentration on a spell, and must make a Constitution saving throw against the lash at the beginning of each of their turns. The target takes 1d6 acid damage on a failure of this constitution saving throw or half as much on a success, and this damage is treated as double its value for the sake of determining the concentration DC to maintain a spell through it. This effect will only end if dispelled or if the affected target washes themselves in flowing water as a full round action. Magical healing does not end this effect.

At Higher Levels. This spell's initial acid damage increases by 1 and the acid lash's duration increases by 1 round for each slot level above 1st this spell is cast with. This spell's base duration increases by 1 minute and its acid damage per round is increased by 1 for every 2 slot levels above 1st used to cast this spell.