Cruel of Heart
Among the Outlaws #57 (x1)
Treachery
Burden
Doom.  

Surge.

When Revealed: Attach to the hero with Curse of Morgoth attached. (Counts as a Condition attachment with the text:"Forced: After an ally enters play, exhaust attached hero to deal 1 damage to that ally.")

...but many took to robbert and became cruel.
–The Children of Húrin