Within Sylvaris, there are seven known planes of existence. The Prime, which is home to Sylvaris, though this is not the sole world. The Prime is a central source of energy from the other six planes and is the center of the planar cosmology. As source and center, the Prime is most often represented by the trunk of a tree when depicted in diagram form.
The symbolism of a tree is accurate in displaying how the planes interact. The trunk represents the Prime. Off the Prime are the six other known planes of existence. Each of these planes is represented by a tree branch and upon each tree branch are sub-planes and realms, depicted as smaller branches off a main branch with leaves that grow upon the branches. Using the ideology that a branch is one of the six primary planes, a smaller branch is a sub-plane, and a leaf is a realm offers a good analogy for understanding how the cosmology works.
Each of the planes has a broad overarching focus for its foundation that is based upon the energy it provides to the system. That is then more narrowly defined by the sub-planes and realms that grow from the specific branch. It is, in fact, the realms and sub-planes that create most of the foundational energy and channel it into the branch which then transfers that energy to the trunk so that it can be distributed throughout the system. This provides each plane, sub-plane, and realm that is connected to the tree energy from all seven of the known planes of existence. The specific type of foundational energy is more potent within its own category, but it is not exclusive to that area.
For example, within the Ethereal Plane is the realm of Time. Time is not something which only exists within the Realm of Time, or even only within the Ethereal Plane. The energy of Time is strongest within the Realm of Time and weakens as it moves into the Ethereal Plane, then to the Prime, and then to each of the other planes and so forth. Time exists within all aspects of the system; it has varying strength and effect depending on where you are experiencing it. The same is true for creation, elemental, magic, nature, and fortune. The Prime is the focal point where all these energies coalesce and take form, as well as a conduit for the energies to reach each other.
It is not currently known where or how the realms create, gather, and generate the energy of the cosmology, nor whatever process they use to provide energy to the system. What is known is that somewhere along the line a corruption began seeping into the energy. The Erid claim it is the force of the great evil that they are preparing to one day battle. The Halflings believe it is from a lack of merriment. The Gnomes insist it is from banality and a lack of creative progress. And so on as each of the peoples of Sylvaris speculate. Whatever the source of this corruption, all planar scholars agree that it does exist, and it is growing stronger. Each plane, sub-plane, and realm is affected differently by it and, to date, only the Sub-Plane of Radiance has remained untouched by its effects, and while various theories exist regarding why, none have been proven.
The corruption has existed for thousands of years, it is growing stronger, and it is widely believed that it is the reason for many of Sylvaris’s ailments. The destruction of Val’Therin, the Fibian wars, the formation of Jex’kor, the enslavement of the Gargoyles, and the dangers in the Myst are often attributed to the corruption.
The undead are thought to be a result of the corruption and it is surmised that without corruption they would not exist. Other scholars argue that they would still exist, but in a different way and with a different impact. The undead often utilize the corruption as a source of their powers, often unwittingly, or without a conscious desire to help the corruption. Their personal desires for power at any cost is often bad enough.
That is not to say that agents of the corruption do not exist within Sylvaris. They do. Those that delight and prosper in the degradation of Sylvaris are often referred to as Demons. Some take exactly the form one would expect when hearing the word Demon: Large horned creatures of fire and brimstone, or beasts of great physical strength that enjoy inflicting pain upon others. While such creatures do exist, they are easily recognized and dealt with when they turn up in the planes. It is the ones that look and act like everyday people, whispering in the darkness, promising power, or other desires in exchange for “favors.” The deal makers, the contract holders, are the ones who truly expand and grow the power of the corruption. They are the ones of which to be wary.
While all the goodly races strive to combat evil wherever it arises, it is the Aeshu and the Erid who have led the charge in battling the corruption. Within the past decade, many Aeshu and Erid demon hunters have found assistance from the Beast-kin in battling these creatures of corruption. It seems the connection the Beast-kin have to the Prime have made them sensitive to signs of corruption and ideally equipped to combat it. The abilities of the Beast-kin and the natural resistance to the influence of corruption have made them powerful allies to the Aeshu and Erid demon hunters.
These newfound allies have renewed hope in the battle against the corruption. Scholars have theorized that this new race, with such diverse traits and a powerful resistance to the corruption, is the cosmology’s attempt to fight back. Others theorize that the creation of the Beast-kin was a planned and deliberate action of a powerful, hidden force that battles against the corruption. Only time will reveal if either of these theories are true or not. For now, be wary of figures who whisper dark deals asking for future favors. Keep happiness in your thoughts and merriment in your heart as you go throughout your day. The system of the planes is proof that, in Sylvaris anyway, the energy you put out into the world spreads far and wide…and does have an impact on what is to come.