draconica's umbral blade

you force your own shadow into a solidified blade of gloom. it silently dances with the music of the shadows. This magic sword lasts until the spell ends. It counts as a simple melee weapon with which you are proficient. It deals 4d8 psychic damage on a hit and has the finesse and light properties. In addition, when you use the sword to attack a target that is in dim light or darkness, you make the attack roll with advantage. also, when you attack whilst under the affects of the spell 'draconica's umbral resonance', you add extra damage equal to that of double the spell level the spell was cast at.

At Higher Levels. When you cast this spell using a 6rd level spell slot, the damage increases to 6d8. When you cast it using a 7th level spell slot, the damage increases to 7d8. When you cast it using a spell slot of 8th level or higher, the damage increases to 8d8.