What I mean by similar scope is the mix of 'was' and 'will be', technology and fantasy, realism and the surreal, prehistoric cannibals communicating with the aristocrats of the outer space oligarchy.

I am looking for books similar to the Dark Tower series in terms of elements and themes they incorporate: surrealism, paradoxes, magic realism, heroic epics and futile endavours driven by the disillusion of the protagonist (the last one's a bit tad concrete).

The problem with such books that it is undeniably difficult to define their genre. You can't name the Dark Tower fantasy, nor is it science fiction; or solely high-fantasy when it's also post-apocalyptic (and in a sense prehistoric). But obviously, a DT reader should catch at least a slight glimpse of what I might be asking for!

P.S. I SEARCHED I SWEAR.