Arcane Dagger

As a bonus action, you draw the sigil in the air before you and flick your wrist, calling up a mote of arcane power that quickly becomes a simple throwing dagger.  You can then use an action to throw the dagger at a target within range, using your spellcasting modifier instead of strength or dexterity to attack and damage rolls.  The arcane dagger counts as a magical attack, thus avoiding damage resistances and immunities regarding this.  The dagger dissipates at the end of your turn, or after seven seconds.  The damage caused by this attack is a base 1d4.   The damage the dagger deals increases by 1d4 at 6th level (2d4), level 12 (3d4) and level 18 (4d4)