Infernal Downpour

Infernal Downpour costs {1} less for each
Legendary creature on the battlefield that
you do not control.
Each player chooses a Legendary creature
they control. Infernal Downpour deals 13
damage to each other creature. You draw a
card for each Legendary creature destroyed
this way.
"Suffer, Waveclaw. And know your place before
the Grimm."