Watch the hands, not the blade

Your deft hands and quick mind allow you to wield a single short blade to deadly effect. 

Whenever you take the attack action you may immediately use your bonus action to Sleight of Hand your blade to your free hand and make another attack roll, this roll is done at advantage. 

Your unusual skill with the blade cause your foes distraction. Your bonus attack can deal an extra 1d6 damage for every odd character level you have (2d6 at 3, 3d6 at 5) for a maximum of 10d6 at level 19. When you use this feature all creatures that see damage added this way can not be dealt this extra damage for 24 hours. 

You can only benefit from these effects while wielding a shortsword, dagger or similar bladed weapon in one hand and nothing in the other.