World Tree

Description:

Scientifically known as the Hyperion-Sequoia Tree, and is made of Hekrum Wood.
A tree, with bark, leaves, branches, shape, and such ranging depending on the region and color changes. But always it's massive, being (at the smallest) big enough to hold an entire fortress, or (at its largest) an entire city. This results in twigs as large as bridges, branches as massive as Grand Canyons, and the trunks practically being wide enough to be a country, and tall enough the bottommost branches of the tree are well above the clouds. Not to mention the roots, should they be magically removed, would leave massive caverns whole villages could live in. The tree is so massive (not as big as the Earth's Heart) that it creates so much energy that anyone near it feels more alive, calm, happy, and so on. At the base of the trunk is a massive door, always covered in intricate markings, symbols, and so on, depending on the tree's location, the location's alignment, and randomizing factors. Though the appearances can vary widely, the description for the World Tree grown at Magna Arbor is used as the basic description.

Personal Uniqueness:

Each World Tree is born and grown to be entirely unique, having its own bark and leaf color and style, as well as uniqueness in the architecture of its structures and so on. This has almost caused each tree's 'style' to be labeled as a manifestation of its 'personality'. This is also seen (or rather felt) by the energy each tree gives off, having a distinct (yet somehow unplaceable) difference from other trees. Because of this uniqueness, this can cause people to more quickly become attached to the tree than they would to any other tree, and as such, should it die, individuals would go through the same symptoms as if a friend had died or an acquaintance/stranger.

Alfeon:

The name for whatever structures and such appear atop the World Tree. The branches on the World Tree (once its grown enough) will start growing structures (style dependent on the tree) that will start as being made out of Hekrum Wood at first, but once fully completed, will slowly change the wood to the proper materials. The size of the tree will also affect the size of the structures.
The only way to get up to the top of the tree is with aircraft capable of flying up to the Stratosphere (since the big trees that manage to reach that high have the lowest branches are at the very bottom of the Stratosphere, and the highest being near the top), or through the door at the base. The inside of the trunk is entirely hollow, forming a massive chamber called the Arcaneous.
Though the trees branches usually reach between 3-20 miles out, at largest, the structures will spread about half the length of the branch length. This leaves the outermost branches being empty except for home to many different ariel animals, or the unlucky (or lucky, depending on your viewpoint) little forest creature, such as a squirrel.

Structure Types:

The Alfeon has many different structure, each with their own usage, appearances, and so on. Depending on the type of tree, the structures can be made of different materials, such as stone, mud, wood, brick, etc. The structures are placed at the top of the Arcaneous, which ends a little bit higher than the bottommost branches. Some structure reach all the way down to the lowest branch, with these having the best view of the ground, though almost all structures can get an at least somewhat decent view of the world below.
Gardens:
An array of beautiful gardens, with their numbers ranging from a single garden, to up to twenty. Their plants and architecture range depending on the region, but they always have Goddess Orchids growing. The basic description is the follow.
Beautiful white arches that lead into the either square, circular, or crescent-shaped gardens with walls on the outside, pathways made of marble tiles that lead between large ferns, rose bushes, Lilies, and similar plants, with the Goddess Orchids of course. If it's a large enough garden, a magnificent fountain will be placed, with a single creature (varied at random of different beautiful mythological creatures) at the top, often made of a gray, smooth stone. Should the garden also be big enough, large trees might also grow, providing shade for those taking a stroll. If these are placed on the edge of structures, then one side might have a railing, so as to provide an epic view of the branches, and the world below.
Arcaneous:
The massive chamber inside the trunk, and the easiest way up. The door to it resides at the base of the trunk, that swings inwards slowly with heavy grinding, allowing light into the dark chamber. Once sentients are inside, many natural lights inside the chamber will illuminate, destroying the shadows. This chamber can be used as a massive room for defense, having many thousands of possibilities, with it allowing for the potential of a Caliber to be used so that soldiers (living or mere animated statues/armor) can be summoned to defend it should the need arise. The only way up the chamber is with wings on your own back, or via the circular platform in the center.
The platform (roughly twenty feet in diameter) will rise up via a system of incredibly strong vines from underneath that can carry almost any weight, though plop a dozen tanks on there and it will go slower, if not fail. One could also abuse this by cutting the vines, causing the platform to fall all the way down. The platform also doesn't raise too fast, causing it to be a slightly nuisance for allies, or a great defense mechanism for enemies. It can be repaired should it be broken, but it will take a while. In the center of the platform is a large bulb, roughly 3 feet in diameter, almost shaped like a pumpkin. This is known as the World Tree Seed, and World Trees can grow from this.
Grand Hall:
Always placed right above the Arcaneous, and often regarded as where a throne ought to be. Always has one grand entryway consisting of a large arch, a carpeted royal walkway up to a massive, multi-colored stained-glass window often depicting a single (but varying randomly) either mythological creature, historical figure, or historical/magical place. Large aches support the curved ceiling, forming massive columns along the wall, with an elegant chandelier hanging from each arch. Most of the materials here are made of a brick that fits the rest of the trees color theme (in the case of Magna Arbor, its gold. The outside looks an awful lot like a cathedral, with the tall spires and bell tower. The path leading up it is often lined with ever-burning elegant torches.
Residences:
These can vary depending on the tree, from simple straw huts, to warm leather covered domes, to square-stucco homes, to hanging silk pods. In the case of Magna Arbor, the residences are fashioned after bird cages, with them usually being about two stories, narrowing at the top, with balconies that give great views, and quietly swinging cage doors on the first floor. The bars are made of steel painted gold, with pure marble between to give the place privacy. Though some spots lack this marble to function as windows. Some are simply tied down to the branches of the world tree, with others hanging by massive chains from higher branches, making access possible via smaller branches grown from below seemingly for the sake of being a bridge.

History:

The first ever world tree was born by the Earth's Heart, being on the smaller side, but was soon felled and became Old Woods (now called Ira's Forest). The second tree to be grown (and a much larger one at that) is at Magna Arbor, forming the castle there as the tree grew right out of the ocean. However, this tree soon collapsed, the branches and leaves piling underneath the castle that was grown (but the branches from above leaving it in ruins) and the two islands were formed over time, but leaving a World Tree Sapling in its place.
Soon after the start of Hero's Dawn in the Darkness of a Cursed Light series, the sapling at Magna Arbor grew to a massive size, lifting the entirety of the island up, keeping the old castle but also adding many other structures. Due to the trees trunk being in the water, the door grew a large wooden platform and dock at the base of the door, allowing access to it.

Death and Growth Period:

Upon death, the tree's branches have a chance of becoming entire (normal sized) trees, should they remain intact enough, this can create whole entire forests overnight. The trunk will decompose and become massive ruins, often being homes to many new creatures, wandering sentients, and so on. This causes drastic change in environments and ecosystems, which heavily discourages reckless cutting down of World Trees. Also upon death, there is a chance that the World Tree might leave behind leave behind the World Tree Seed (should it remain intact) this will cause a new world tree to sprout. Once the World Tree Seed is planted, after two weeks it will decide if the environment is good enough. If it is, the ground will rise up slightly and a very small plant will appear. If not then the entire seed will unbury itself.
Following the tiny plant period, the seed will slowly grow, becoming a 5-foot tall sapling, then eventually a 15-foot tall tree with bark like silver and leaves like gold. It will stay in this state until one of the follow criteria is met.
1. Nourishment is received from the Earth's Heart, in which case it will grow rapidly, reaching full size in a matter of three years with fully completed structures and so on.
2. A being with a sufficiently powerful Caliber that can influence plants uses it on the World Tree, forcing it to grow rapidly. This can however, cause the tree to grow rapidly in unhealthy and unstable ways.
3. One of the Higher Ones uses divine ordination to cause the tree to grow to its maximum size, this can happen as long as ten years, or in as little as six months.
4. The tree will slowly grow to full size after 1000 years, staying the same size until a hundred years has past, in which case it will experience a growth spurt, growing 10% of its max size.

Ozone Layer:

Since the top of the tree reaches into the Stratosphere, the entirety of its leaves is surrounded by Ozone, which is normally harmful to plants. However, the tree actually benefits from the Ozone, using it to fight infections off with immense efficiency, purify the water it absorbs, and also draw in an immense amount of Ozone to flood its trunk as a defense mechanism. The tree also needs its branches and leaves this high to absorb the higher UV-light intensity, which is required for it to grow to this size. Due to it also being in the Ozone layer, it serves as a triple protection, from it being incredibly high up for lack of air, the poisonous Ozone gas, and the altitude preventing most conventional aircraft from reaching it.

Protective Bubble:

Since the branches are in the Stratosphere, normally nothing else could live up there, but due to the massive amount of leaves the World Tree has, it produces so much oxygen that a massive bubble (extending out about a mile from the edge of the leaves) that lacks ozone and has enough oxygen to breath is made, allowing for the presence of other creatures. This causes an effect at the edge of the bubble where the air seems to ripple as if from heat, almost forming a shield against anything that isn't aircraft, further making the tree defensive. This bubble is large enough as well (and the same density as air down on the ground) that aircraft can fly around in it, and any winged creatures can enjoy flying above the clouds.

Root Saviors:

At the base of the tree, the roots sprout up at most a mile. They can be easily used as defensive positions, walls, and so on, making great defensives for the tree. They also help stop the tree from toppling by any means, making it so the trunk has to be cut 100% through before it can be felled (and being massively destructive when it does). These massive roots also extend underground for miles and miles, allowing it to reach massive water reserves that it needs in order to survive (even though it's very efficient (as required) to pull water from the air. Though if it's right next to the ocean, it will lose this ability and completely focus on drawing water from the ocean, allowing it to grow to the biggest sizes. In this case, it will create an area on the other side of the trunk, opposite the gate, where it will dump all the salt). Should one actually be able to get into these massive roots, they can produce an almost limitless amount of water to survive off.

Evergreen:

Even in winter or extremely cold months, the tree will still have leaves, though not always green. For example, the World Tree at Magna Arbor will have green leaves in summer, orange/red/yellow in autumn, silver in water, with the leaves turning to pink blossom leaves in spring. The sheer massive amount of leaves that would fall to the ground each autumn would simply be catastrophic for an area over several miles.
Not to mention, the massive amount of leaves keep the place warm, even against the severe cold in the stratosphere. However as the seasons change, the leaves lose a bit of their protection, allowing the branches and the structures to experience normal seasons. Also because of the massive amount of water moisture in the leaves and such, clouds will often form in the (most often) highest branches, causing normal weather for the structures far down below. Even though one might suspect the massive amount of leaves would block out the sun entirely, sunlight still manages to find its way down through the leaves perfectly, causing only the trunk below the leaves to cast a shadow, with it fading out at the very end.