[SPELL] Blood Boil

Blood Boil has a casting value of 6. If successfully
cast, pick an enemy unit within 18" of the caster
that is visible to them. That unit suffers a mortal
wound. If a model was allocated any wounds
caused by this spell but was not slain, roll another
dice. On a 4+ that model suffers another mortal
wound. If the model is still not slain, roll another
dice. It will suffer another mortal wound on a 4+.
Keep rolling dice in this way until either the model
is slain or you fail to cause a mortal wound.