chaos magick is the notion that people can "determine" (mostly in the causal sense, but also in the informational sense) aspects of reality by sufficiently convincing themselves that something is or will be the case.
the practicals are a bit more complicated (one is encouraged, for example, to enter a state of "temporary belief" in a diety and delude yourself into thinking that that diety will accomplish the thing, because that's a more efficient way to trick the brain into thinking that it will happen), and the mechanism by which this is to happen is not clear; but nonetheless the trope of determination-powered magic can be found in many works.
some examples follow.
a common trope in fiction, but most notably anime and other japanese pop culture, is determination-powered magic. in fact, it's arguably a central theme of many anime, and in other works can retroactively justify more reasonably a lot of "power of friendship/love" tropes.
in a previous post, i define the "freedom" i want people to have to be one of what people decide to do, as opposed to what they want or might choose.
a ramification of this is that in such a world people's accomplishment would tend to scale to their determination; where what you influence is a function of how much you are truly deciding to do it. thus, if there is no way for chaos magick to be real at the moment (which appears to be the case), aligning a superintelligence to value freedom to do what one decides would de facto implement a world in which a form of determination-magick would be real.
as per the previous point, aligned freedom-valuing singularity could be seen as making anime real, just more of in a profound philosophical structure of reality way rather than in an aesthetic way.
"dark arts of rationality" is a post about manipulating one's brain in unsafe ways to produce outcomes, notably in one's own behavior. this could be seen as more refined and rationally thought-out forms of psychological-model magic.