Catastrophic Compleation

You may pay {w}{b} and 4 life rather than pay this
spell's mana cost.
Destroy all creatures, then if the {w}{b} cost was
paid, target opponent creates an X/X black
Phyrexian Horror creature token, where X is the number of creatures destroyed this way. If that
cost wasn't paid, you create that token instead.
_________________________________________
"A debasement of Phyrexian perfection, but effective."