A Russian who denies the existence of anything but Tolstoi. The leader of the school is Tolstoi.

One who advocates the doctrine of nihilism; one who believes or teaches that nothing can be known, or asserted to exist.

an advocate of anarchism

a man who judges of the world as it is that it ought not to be, and of the world as it ought to be that it does not exist

In the context of Buddhist teachings, someone who, upon hearing about emptiness, comes to the mistaken conclusion that nothing exists; for example, that there's no cause and effect of actions or no past and future lives.