...and the destruction of Common Sense
A section from the Alchemist's Manual: The First Pill
It is a known fact that in order to reach the very limits of aether cultivation, there are two things all warriors need: a good formula and compatibility.
Aether formulas serve as the platform on which a cultivator builds up their entire future upon.
A good formula means a good foundation, which in turn means a bright future.
However, not all formulas are created equally, hence why we have rankings for them.
Additionally, not all cultivators can use all formulas.
Much like how architects need to figure out the right foundation in order to build their buildings upon and find the right materials appropriate to the area, it is up to the would-be Aether Warriors to find a formula that is the most compatible with them.
In an ideal world, all formulas would be the highest rank possible and all warriors would have access to formulas they would have maximum compatibility with.