Irithix, Formless Contagion

Voidlord (Irithix must be your commander.)
Split Second. {x} may only be paid with {c}
If your devotion to {c} is less than 10, Irithix isn't a creature. When Irithix is a creature, it cannot be
removed from the battlefield.
All mana sources only produce X {c} equal to that players devotion to colorless.
At the beginning of each players upkeep, they
lose life equal to the number of {c}mana sources they control.
Irithix's Power and Toughness are X.