I like the idea of spells knocking down armor, so let’s keep working on that theme.
1st level evocation
Casting Time: 1 action
Range: 50 feet
Components: V, S
You point at a target in range and make a ranged spell attack. On a hit, blades of force shoot from your fingers and slice the targets armor rending it and reducing its effectiveness. Until the armor is repaired, the AC of the target is reduced by 2. If the target armor is natural armor, then a long rest will repair the armor or any spell that heals 5 hit points of damage will also restore the armor. If the target has no armor or receives its armor from ability scores alone, then this spell has no effect.