Marxists are not anarchists or communalists. Marx saw the failure of the Paris Commune and of the Utopian socialists and sought to create a theoretical framework that could be used in conjunction with practical political programs to resolve class struggle over time, which he predicted would ultimately produce a stateless society. This transitional society, to contrast with Marx's name for liberal capitalism -- the dictatorship of the bourgeoisie -- is referred to as the dictatorship of the proletariat.

"State communism" is, uh, just made-up as far as I can tell. Marxists support the destruction of dictatorships of the bourgeoisie and their replacement with dictatorships of the proletariat. Generally they would like to see a stateless society one day, but they understand that a simple commune would get steamrolled the instant it became politically important enough, so they are principally concerned with making states democratic in a truer sense of the word than liberal democracy -- which is de facto controlled by the rich -- in order to end "capitalist encirclement" and make things like communes more viable.