Shadow Bone

You strike out with a bone-infused with a wayward spirt.  Make a melee attack, dealing 2d6 + MOVE ghost damage on a hit. On a natural attack roll of 18 or higher, the target’s AC is decreased by 1 while it remains in battle. This decrease may be stacked up to a maximum of -5 to AC.

At Higher Levels: The damage dice roll for this move changes to 2d8 at level 5, 4d6 at level 10, and 6d6 at level 17.