Kadulith, Dead but Dreaming

Kadulith, Dead but Dreaming, can't be
countered.
Whenever Kadulith or another Nightmare
enters the battlefield under your control, if
you control ten or more Nightmares or
Dreams, you win the game. Otherwise, you
gain six life, draw two cards, and exile up to
two target permanents.
A dream as vivid as the world itself.