The Powers play roles in the Cat stories (some of them) and are central to the three-volume alternative history set that starts with A Carpathian Campaign. They also appear in the novella “Cities and Throngs and Powers,” and in two stories in Tales from the Upland They choose a few humans and others to act as their avatars, so to speak, in exchange for knowledge of the land. But what are they?
Short answer: I have no idea.
Longer answer: They are living creatures that depend on overspills of energy from the plants and animals living in and on each Power’s territory. Although there are one or two who get that energy in less positive ways, such as the Power that claimed Kutna Hora in Czechoslovakia. Even the Habsburgs don’t poke it too closely, and the Power that resides in the rest of Bohemia leaves it alone. You see, there are stories about a battle…
In many ways Powers are part of the landscape they inhabit, and help encourage the health and stability of that landscape. For example, Logres in Britain gives Rada Ni Drako insight into anything that might be disturbing the land, especially if it is an outside entity such as she encountered in Wales (When Shadows Claw). The Power of the Matra helps connect the members of House Szárkány and warns the Head of trouble such as forest fires that threaten to grow beyond healthy bounds, or if a mine is dumping chemicals into the soil that should not be there. The down side is that the Powers expect these problems to be fixed, or will use their fleshly avatars (the Guardians) to do the work. Logres in particular has no qualms about overriding its Guardians and using them with no prior warning, leaving them exhausted and mentally bruised. Pannonia likewise, and Logres and Pannonia have burned out multiple Guardians over the centuries. That is in part why the Habsburgs have an individual who acts as buffer between the actual Guardian and the Powers. Rada, alas, gets the full brunt of Logres’s will and energy demands.
Some of the weaker Powers are slightly more understandable to humans, I suspect because they have adopted some human characteristics over time as a survival trait. But Pannonia, Logres, Kutna Hora? So alien that even Rada doesn’t want to try to understand what makes their minds tick. They are amoral, especially Logres and Pannonia.
They consume energy to survive. It is a form of energy not used by the other creatures living on Earth, so Powers only compete with other Powers, most of the time*. It comes from living beings, and in some ways from the land itself, built up over millions of years. When a Guardian looks through a Power’s awareness, he sees points and flows of energy, shaped and directed by the Powers and by natural forces. One job the Guardians have is to stop those flows from getting fouled by other humans, and the Powers generally have no compunction about burning out their avatar in order to do that. Rada has come close, and István Eszterházy will probably end up scorched if Pannonia overloads Rudolph and the energies overflow toward the Matra.
Can the Powers die? Oh yes. What happens when they do… You’ll see this fall, when Clawing for the Crowns is released.
*Certain human behaviors and actions can tap those energies and twist them, in effect poisoning the Power and the land. Not with chemical pollution the way we usually thing about it, but consider the WWI battlefields, or the area Timothy Snyder called the Bloodlands.