Ambush Shard

Launch a projectile from a distance removed from the caster, so as to strike the enemy from behind. Make a ranged spell attack against a creature within range. On a hit, the spell deals 3d8 force damage. This spell ignores any bonus granted to AC by a shield. The target takes no benefit from cover of any kind.

Additionally, if you cast this spell within 5 feet of your target you gain advantage on the roll. This spell ignores the typical disadvantage that would be present when casting ranged spells within 5 feet of a hostile creature.

At higher levels. When you cast this spell using a spell slot of 3rd level or higher the damage increases by 1d8 for each slot level above 2nd.

*original idea from Reddit user u/Hollow_Assassin*