Phyrexian Mitigator

When Phyrexian Mitigator enters the battlefield,
each player loses {x} plus 2 life, where X is the
amount of red mana spent to cast Phyrexian
Mitigator.
When Phyrexian Mitigator leaves the battlefield,
each player sacrifices {x} plus 2 nonland
permanents, where X is the amount of black mana spent to cast Phyrexian Mitigator.