Memvlir, the Altraz Guardian

Memvlir, the Altraz Guardian cost {1} less for each creatures on the battlefield.
When you cast Memvlir, the Altraz Guardian,
place a Frostbite counter on X target creatures
where X is the number of CMC you spent to cast Memvlir, the Altraz Guardian.
{s}{s}{s}; Exile Memvlir, the Altraz Guardian. You
can then cast Memvlir, the Altraz Guardian from
exile any time for {p/g}{p/g}{p/w}{p/w}.