It's a huge tree of legend that's said to connect the heavens, the earth, and the underworld.
The World Tree (世界樹), also known as the World Spiral Tree (世界螺旋樹) or World Twin Tree (世界双樹), is an enormous tree consisting of two immense, arching trunks intertwined in a helix-shape, with branches that scrape the sky. It appears in place of Ganishka's twice reincarnated form after Femto uses a stroke from the Sword of Beherits to split open the apostle. At the foot of the tree sits the city of Falconia.
The World Tree is ground zero of the Great Roar of the Astral World, and is explained by Gedfring to be the source of the global Interstice unifying the Physical World and Astral World in the form of Fantasia. The archmage describes the tree as a massive fissure piercing deep into the physical and astral realms. Prior to its arrival, the World Tree's growth was being stymied by the spirit trees of the Interstice, which absorbed power from it and hindered the expansion of its branches into the Physical World. With the burning of such spirit trees by Griffith's forces, the World Tree has grown rampant in a manner reminiscent of the chaos of ancient times.
The omnipresent spread of the World Tree's branches allow for the use of them as "sky paths" (空の道), which connect two disparate points in space, allowing for traversal across large distances that is experienced as if "[riding] through the sky [...] in the blink of an eye". Such sky paths can be navigated through corridors of stone pillars, allowing for high-speed traversal between preestablished locations, particularly by large groups of individuals at once. According to Sonia, among the Band of the Falcon, only herself and Griffith can safely navigate the sky paths. The Moonlight Boy likewise can traverse sky paths, appearing as a shooting star in the night sky while zipping through the branches to his destination.
Attempting to navigate sky paths without the required perception to do so has severe consequences. Those who attempt as much are most likely to become lost among the countless forking branches and end up somewhere unexpected, such as in the middle of the sea or even deep in the earth.
- "World Tree" is an alternative name for Yggdrasil, a tree of similar prominence to this one in Norse cosmology.
- Falconians believe the World Tree to be the source of the ever-fruitful harvest season of Falconia's surrounding land.
- On clear days, the branches of the World Tree can be seen in the open sky, and sailors can use them like constellations in broad daylight.