Mercy is weakness

Use this Stratagem in your Shooting phase or the
Fight phase, when an IRON HANDS unit from
your army is chosen to shoot with or fight with.
Select one enemy unit. Until the end of that
phase, every attack made by a model in that
IRON HANDS unit from your army that can
target the selected unit must do so, but when
resolving such an attack, an unmodified wound
roll of 6 wounds the target unit twice instead of
once.