You weave together threads of shadow to create a knife of solidified gloom in your hand. This magic knife lasts until the spell ends. It counts as a simple melee weapon with which you are proficient. It deals 1d4 psychic damage on a hit and has the finesse, light, and thrown properties (range 20/60).   If you drop the knife, it dissipates and the spell immediately ends. If you throw the knife, it dissipates and the spell ends immediately following the attack.   The knife’s damage die changes when you reach certain levels: to 1d6 at 5th level, and to 1d8 at 11th level. When you reach 17th level, the spell lasts until dispelled without requiring concentration.