Briar Barbs

You hold a thorn or barb in your hand and point to an item within range. The object is covered in thorny barbs, the object does 1d4 piercing damage at the beginning of each turn the person is wearing or holding the object. Each turn you need to make a con save and depending on the object that gets the briars will do a different thing. If the spell is on a weapon, failing a con save will cause you to drop your weapon and it would take a full action to pick it up. If the spell is on armor, falling a the con save will drop your speed to 0.  If the object is a melee weapon it also does an additional 1d4 piercing damage, if it's armor unarmed strikes done to the wearer do 1d4 piercing to the attacker. For every 2 levels higher, the damage increases 1d4.