Aura Corruption

Target aura enchantment spell that would target
a single creature targets another creature of the
aura enchantments casters choice instead.
If there are no legal targets, the aura
enchantment is countered and you create X 1/1
corrupted black and green Saproling Tokens,
where X is is the casting cost of the targeted
aura enchantment.
"Corruption can be found in all things, even pure
ones." - Cryptic Inscription on a tree.