Stephen King's epic fantasy tale, The Dark Tower, is coming to theaters and there's no time like the present to get a good lay of this fictional land. From the trailer, it's easy to spot the heroes of this tale, you may be prone to missing the antagonist. As it happens, The Crimson King is the main antagonist in addition to the Man in Black, played by Matthew McConaughey. But who's The Crimson King in The Dark Tower and why does he matter so much if we actually don't see much of him in the trailer?
As it turns out, The Crimson King is actually kind of a huge problem because he is hellbent on destroying worlds. Not exactly the sort of guy you want to grab brunch with. In fact, on The Crimson King's Dark Tower Wiki, fans get a real sense of his vibe with a quote from the books: "I am the Eater of Worlds." Did you just feel a shiver run up your spine?
The Crimson King's Wiki additionally makes it clear that this antagonist's primary goal is to bring down The Dark Tower, which connects multiple worlds, and bring about Discordia, or the general state of chaos which would most likely ensue when The Dark Tower crumbled and those vital inter-worldly connections were broken. In this way, The Crimson King would be able to refashion various worlds for his own purposes and, as he believes, re-make the world (assuming he doesn't perish in the process, like many others would).
In July 2016, McConaughey posted a teaser image of The Crimson King's sigil with the phrase "All Hail" written below it (whether that's meant to be red paint or blood is up to interpretation really). He captioned that image with his own quote from the books: "Shake the hand that shook the world."
It would appear the McConaughey will be acting on behalf of The Crimson King in The Dark Tower as the Man in Black. As ScreenRant reported, it would seem that The Crimson King will be a nebulous threat in this first film (with possible sequels actually bringing him to life) while the Man in Black does his bidding. This brings McConaughey's post full circle as it appears he's totally in character, warning his Twitter followers about The Crimson King as if he were in character.
All in all, it sounds like you wouldn't want to write off The Crimson King completely. Just because you can't see him, it doesn't mean he's not at work trying to bring about the end of the world. Be careful.