Honestly, I believe this ability is more accurately categorized as Mathematics Manipulation rather than Concept Manipulation.
The reason is that Sandrone has explained on several occasions that mathematics is a fundamental aspect of the world. In this instance, she does not manipulate concepts directly, instead, she manipulates possibilities via the "World Formula," which is essentially a mathematical calculation system.
These possibilities originate from a single starting point before branching out into numerous other potential outcomes. Sandrone employs the World Formula to reverse this process. For example, if ten possibilities have stemmed from one initial possibility, she collapses those ten branches back into the single original state.
This is why fused, damaged souls can be separated back into individual souls, restoring them to their proper state. In other words, what is being manipulated is not the concept of the "soul" itself, but rather the mathematical structure governing the branching of possibilities within that world. Maybe, posibility manipulation, mathematics manipulation and restoration, seemfine to me
Yeah, perhaps this is better discussed in a separate CRT, since this ability would only be acquired by Sandrone.
By the way, I disagree with the CRT.