Miasmal Shroud

If successfully cast, pick 1 enemy unit within 18"
of the caster that is visible to them and roll
three dice.
For each 5+ that unit suffers 1 mortal wound.
In addition, if you rolled a triple, subtract 1 from
hit and wound rolls for that unit until your next
hero phase.
If you rolled a double, subtract 1 from hit rolls
only for that unit until your next hero phase.