So far, from Fire’s descriptions, it sounds like Emperor Black goes straight to Core Intention; super-focusing intention itself. How one applies that energy is up to the individual user (e.g., physical effort, wealth, skill or information mastery, business influence, establishing presence, material/intellectual/spiritual Empire-building, etc.,); but the effect is happening at the Source.
It sounds like a hyper-Power-Up for the will itself. Single-minded willpower, attention, and focus.
That sounds like it could be applied to anything.
But it would need to be used in moderation.
It may be something like a hyper-contraction. In order to preserve balance, there might also need to be times of relaxation, expansion, and letting-go.