As an action, you pierce a creature that you can touch or see within 10 meters to the core with shadow for the duration. At the start of each of its turns for the duration, the creature must make a Fortitude saving throw.
On a failure, it takes 3d6 necrotic damage and rolls a d6.
On a roll of 1–2, the shadow spreads to the legs. It is immobilized until the start of its next turn.
On a roll of 3–4, the shadow spreads to the arms so the creature has disadvantage on attacks until the start of its next turn.
On a roll of 5–6, the shadow spreads to the head so the creature is blinded until the start of its next turn.
On a critical failure, it takes twice as much damage.
On a success, it takes half as much damage and and the effect ends.
On a critical success, it takes no damage and the effect ends.
You can increase the damage by 4d6 for each additional mana expended.