To put it simply, the universe is not as solid and stable as it appears to be, but actually exists in a state of constant flux on every level, with an incalculable number of changes happening literally everwhere all the time, so fast and so subtle that even the most advanced instruments can only catch a very superficial glimpse of.
The reason the universe doesn't constantly reality warps itself to hell and back is because these fluctuations are naturally "channeled" in a way that allows the macroscopic stability we are familiar with, and makes continued existence possible.
With Meta Probability Manipulation, you can reach out to these primordial fluctuations, unlock and harness their true potential, allowing you do dynamically reshape and redefine anything on any level, since the limitations of each level are determined by the stabilized probabilities of the previous one, and can be lifted alongside them.
As a result, you end up "bending the underlying currents of fate and dynamically reshaping reality like an artist would" without any real limit. And that's just for our real-life material universe. Throw in supernatural phenonema and metaphysical realms, and you are barely one step below full Omnipotence.