Curse of a Dwarf
The Betrayal of Mîm #191 (x2)
Treachery
Curse.  

When Revealed: Attach to the hero with the highest printed (Counts as a Condition attachment with the text: "Limit 1 per hero.Forced: After the attached hero destroys an enemy, deal damage to the attached hero equal to that hero's printed Then, discard Curse of a Dwarf.")