No-Ship 'Ithaca'

Crew 2. Only legendary creatures can crew this vehicle.
Flying, Vigilance, Ward 2.
{t}: Exile target creature you control. At the
beginning of your next end step, you may
return that creature to the battlefield under it's
owner's control. Then, if you own four or more
legendary creatures exiled by No-Ship 'Ithaca,'
you win the game.