The Descent: Journeys in the Dark (Second Edition) Wiki

What Doesn't Kill is the base Plot Card from Skarn's Twisted Soul Lieutenant Pack.

What Doesn't Kill You
No Cost to Purchase
Exhaust this card when a monster suffers 1 or more Heart. If that monster was not defeated, it recovers 1 Heart. Mark that monster with a threat token from the supply. Each marked monster adds 1 brown die to its defense pool.
Twisted Soul 1/12 1 Threat