Mark of Shadow

The Mark of Shadow is one of Dea'Koh's marks. It was first encountered in the Void of Shadow as the group was passing by Moongazer mountain. It was gained by defeating the champion of Thia'Vulen that harbored one of the aspects of Dea'Koh. It was originally wielded by Patience until his death, it is now wielded by Gin Tatsumaki.

Shadow Power - Invisibility
As an action you can activate your mark to make yourself invisible for one hour. After activating this ability make a DC 10 sanity saving throw, on a failed save you take a point of corruption. Anything you are wearing or carrying is invisible as long as it is on your person. The ability ends for you when you attack or cast a spell. You must take a short rest before you can use this feature again.

Shadow Power - Spectre strikes
As a bonus action you can activate your mark to summon three purple spectres of yourself that attack in rapid succession. The spectres each make a melee weapon attack using your same statistics, each attack roll has advantage. Each Spectre fades after it strikes out quickly. After the attacks make a DC 15 sanity saving throw, on a failed save you take a point of corruption.. You must take a short rest before you can use this feature again.