Gods, Demons and you
What is a Power
A Power is a sufficiently powerful immortal being who still has an interest in the mortal realms. Whatever they style themselves as matters little. From the viewpoint of an adventurer they're all more or less equal. While indeed very powerful, they can be countered, thwarted and even defeated by resourceful and powerful adventurers.
How much power do the Powers have?
A lot. An awful lot in fact. But no Power is omni-anything. A priest may claim their god is all-seeing but the reality is a little less. Odin, as an example relies on the Ravens, Thought and Memory quite a bit and they certainly can be fooled, evaded or captured. Not easily mind, but it is doable.
What sort of Powers are there?
The dominant religion of the Baronies and Western Kingdom is that of the Western Church. The head powers style themselves 'Archangels' or 'Powers of Light' and rumour (true) has it that they are ascended Elven factions that have coalesced into a five powerful entities. They formed in direct opposition to the formation of the Demons or 'Powers of Darkness', many of which were elven sorcerers of incredible power who ascended and transformed into powerful and often malevolent beings. For some reason the Powers of Light have watched over the humans developing in the shadow of the Elven empire, supplanting whatever Gods were there to begin with.
A Power of Light is concerned with civilization and stability. Magic and magical ability is seen as destabilizing and disruptive to what they perceive as the 'natural order'. Magic is often regulated by religious ritual. Because their goals are social and often altruistic they can be considered 'good'.
A Power of Darkness by contrast has quite alien or bizarre goals that only itself (if then) understands. Since these designs often come into conflict with the functioning of a stable and sane society they can be considered 'evil'.
Within the Western Kingdom you occasionally find small cults worshiping a Power not associated with either the Powers of Light or Darkness. These are the 'pagan' gods and are either remnants of whomever the Powers of Light supplanted or even more recent newcomers. Outside of the Western Kingdom these collections of Powers are more established in their home regions or societies.
All of these Angels, Demons, Gods or whatever are of roughly equal power. What is different is their skills, subtleties, experience, moral codes and specialties. The Powers of Light are a credible threat and counter to the Powers of Darkness because the former work together and the latter will betray any alliance and sooner than later. For much the same reason powers and gods in other areas will form groups for mutual defence, assistence and recognition.
Avatars, Projections and Minions
Powers are typically incapable of existing on the normal planes of existence for a number of reasons. Also, to visit requires the cooperation of a local entity performing an incatation. This may be a spell or ritual or even the foolish action of mentioning the Powers given name thrice. Typically the Power will respond with a minion or projection.
A minion is a entity constructed by and / or a follower of the Power. The best known of these are Imps and the larger Devils that are used by the Powers of Darkness. Minions may also appear as an animal favoured by or asscoiated with the power. In any case the minion is a powerful intelligent entity with a variety of powers. Most are free willed (or a willfull facsimile therof) and usually have the powers best interests in mind. Minions act as messengers and go-betweens. They represent a minimal risk on the powers behalf or when they want an eye on events but are too busy to actually do it themselves.
A projection is an insubstantial form of the power. It appears as a translucent projection or as an animated object eg a tree forming a face out of the bark or a reflection in a pool. Alternatly a projection will possess a willing suplicant and speak through them. In all cases all a projection can do is talk. Whether some of the Powers magical persuasive abilities work depends on the local conditions. Projections are used when the Power just wants to talk, is wary of what's going on or those doing the summoning want limits on what the Power can do.
An Avatar is a physical construct capable of interacting with the material universe and is directed by a portion of the Power itself. Avatars are difficult to construct and control and loss or destruction of an Avatar causes the Power actual pain and loss proportional to the size and power of the avatar. The examples seen in the Powers section represent a 'minimum response' avatar, the loss of which is equivalent to a bee sting or stubbed toe. Constructing a new avatar for that particular plane typically takes a month. Avatars are the Power's most personal and risky response. The actual suffering to the Power is minimal but avatar loss removes their most potent tool for acting in an area. Some adventurers summon and destroy a potentially rival avatar. This is a good way of cutting down the opposition before starting. Others just take a perverse pleasure in denying a power access to the material plane.
Followers and Agents
Powers have mortal minions to carry out their whims. The power gets a set of hands (or tentecles or flippers) on the material plane and the follower in return may request aid of the power and/or it's minions. Depending on the nature and potency of the request the power may grant the request. Using the power's ITN and certain rituals to bind and compel it will be more effacious than a frantic plea for help.