For major races, we have set it at those five, the four lesser tribes and the fifth large central nation. There is not much room for too much else. Although, there is no reason there can not be more minor races/tribes, living in the gaps and corners of Cyprus, but those do not need much pre-planning.

Edit: Here is the next section of the OP.
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Keepers:

As mentioned before, you exist through your Avatar, which is your physical body. As a Keeper, you can wield quite potent power and abilities, although greatness in one aspect generally requires trading off some other ability. While you could be an all-rounder, Keepers typically focus on a particular theme or element, which allows them to allocate more of their power to those abilities. You are free to modify your Avatar and develop new abilities in your Heart at any time, provided you have the power to do so.

Keepers gain power passively from the land and people under their control. The amount of power you have is determined by how much you have conquered, how big your Dungeon is, and how many slaves you have under you. Clearly, a Keeper who has only razed a few villages, lives in a hovel of a Dungeon and has only a meagre collection of slaves will be greatly outmatched by a Keeper who has conquered cities, lives in a fortress Dungeon, has numerous outposts and has whole townships of slaves. Now, a quick way to gain power is to conquer other Keepers, because in doing that you assimilate their Dungeon, slaves and conquered lands into your own and gain their power.

Should your Avatar be killed, that is not necessarily the end. Your creatures will likely be thrown into chaos and slaves all escape unless you have good Constructs to keep them in line, and your Dungeon operations will likely be crippled, but Keepers don't die that easily. Provided your Heart is intact, you are able to resurrect yourself and rebuild your Avatar in the Heart. This process is slow and will take a while, so in that time you just need to hope that your enemies don't come in to finish you off. However, if you die and your enemies have destroyed your Heart, then things go from bad to worse. Your armies will be dead or scattered, your Dungeon assimilated into your enemy's own domain, and resurrection will be difficult. Should you choose to stubbornly persist, you would be back to square one, as if you had come fresh out of the Void.