Shadow of Fear
Khazad-dûm #27 (x3/x1)
Perfidia

When Revealed: The first player attaches Shadow of Fear to one of his heroes. Counts as a Condition attachment with the text:

Limit 1 per hero. Attached hero cannot exhaust or ready and its text box is treated as if it were blank.
Action: Pay 3 resources from attached hero's pool to discard this card.