Whenever you hit a creature with an unarmed strike while you have Shadow Arts die available, you can use your Dexterity, rather than Strength, for attacks and damage rolls with it. In addition, you can roll the Shadow Art die for the damage, turning the damage into necrotic (without spending the die). You can choose to spend the dice to make an additional attack using your bonus action.
You hurl blades made of pure darkness on your foes. You can use an Action make a ranged weapon attack against up to two creatures within 30 feet. On a hit, you cause damage equal to the number rolled on the Shadow Art die (expending it) plus your Dexterity modifier plus half the number rolled on your Shadow Strike dice.
As a bonus action while in an area of dim light or darkness, you can conceal your presence. You become invisible for 1 minute, until you make an attack or until you are in an area of bright light. Once you take this bonus action, you can't do so again until you finish a short or long rest, unless you expend a Shadow Arts die to take it again.
When you deal damage to a target with your unarmed strike, you can force the target to make a Constitution saving throw against a DC equal to 8 + your proficiency bonus + your Dexterity modifier. If the save fails, the target is blinded until the end of your next turn.