Corroding Spear

You fling a small spear-like projectile at a creature, causing corroding acids to chew through their defenses temporarily. Make a ranged attack at a creature within range. On hit, you deal 2d12 Acid Damage. A creature that is hit has their AC reduced by 1 until the start of your next turn.

Using a Higher-Level Spell Slot: The damage increases by 1d12 for each spell slot above 2, and the ac reduction increases by 1 for every other spell slot above 2.