This spell was first originated when those studying the early potential of
magical powers. When they were first trying to conjure magical forces of any
kind, they accidently summoned a very unstable form, which immediately
exploded in their faces. Some time later, when magic was being used as a tool,
as a  weapon, someone remembered reading about that early accident in some old
scrolls. They went back and found the old chants and after some research,
refined the spell into a form that  was easily and safely used. The resulting
spell is able to summon small glowing spheres of energy, that resemble the
spores of some plants, that sail towards the target and explode.