Tide of Serpents

Tide of Serpents is a spell that has a casting value
of 7 and a range of 15". If successfully cast, pick 1
enemy unit within range and visible to the
caster. Roll a number of dice equal to the
number of models in that unit. For each 5+,
that unit suffers 1 mortal wound.
The caster calls forth a carpet of writhing
snakes that brings down the enemy through
hundreds of poisonous bites.