Shadow Strike

You have learned to channel your vital force into your attacks.
You may use an action to perform a Shadow Strike:
roll your current Might die and lose an amount of
Hit Points equal to (number rolled ondie). If this didn't reduce your Hit Points to 0, you may perform a free
attack with a weapon you have equipped:
if this attack hits one or more targets, it deals extra
damage equal to (SL+die). However, all damage
dealt by this attack becomes dark and its damage type
cannot be changed.