Curse of Years

Pick 1 enemy unit within 18" of the caster
that is visible to them and roll 10 dice.
For each 6, that unit suffers 1 mortal wound and
you can roll an extra dice. For each 5+ on these
extra dice, the target suffers 1 mortal wound.
Keep rolling dice in this way, inflicting mortal
wounds and reducing the roll needed to cause
them by 1 each time, until either no wounds
are inflicted or the target unit is destroyed.
A roll of 1 always fails