Once thought to be a legend, Buddy Trees were recently rediscovered in remote locations on several of the continents. Mysteriously though, this locations are difficult or sometimes impossible to find again, leading some to believe that these locations are in fact pocket dimensions, or perhaps that there is only one Buddy Tree that changes its appearance each time its seen depending on where it is located. The Buddy Tree once grew solely in Wing Alayna, and, as the legend goes, would bear vastly different fruit per year. Another legend states that a guardian of time lives in the knot of the tree, connecting the world to the lands of legend.
It was also once thought that the Storydancers came from the Buddy Tree or perhaps lived in it, or even used it as a portal to visit the lands of legend and bring back tales. Though there does seem to be a connection between the Buddy Tree and the Storydancers, it is unclear at this point whether that connection is merely mythical or has some substance to it.
Storydancers are a particular kind of Dancer Buddy that carry scrolls with them and regale their audience with tales as they perform their dance routines. As they travel about without a home, they often take up residence in the Queen's palace, or stay with a host family before moving on. There are no known Storydancer mixes, and if you ask them why, they'd probably reply that they love story more than the idea of settling down.
Why the localization “Tree of Emptiness” isn’t very good
The original term is 「 空想樹 」which means, quite literally, “Fantasy Tree” (or Tree of Fantasy). Now I understand why this name doesn’t strike fear to your hearts, and “Tree of Emptiness” sounds more badass. However, it’s very very important to Cosmos in the Lostbelt narrative to keep the “fantasy” here. Because since Moonlight Lostroom (and before, even with Epic of Remnants thematic keywords involving fantasy and fiction) there has been built up and hints of how do pruned timelines suddenly can appear on the planet even thousands of years after they ceased to exist, with a rich continuation as if they never pruned. Why did Kirschtaria say “turn the fantasy tree a reality” in Atlantis. When you use “emptiness tree” it lacks the nuance they are trying to convey. This is why (Image heavy. Spoilers for Olympus and Avalon Le Fae):
Simulations.
Simulations run by Chaldea equipment, most certainly. Yes, this entire operation started in Area 51 (where and when is this Area 51, we don’t know yet but can’t be the present timeline), but Chaldea is involved.
During Olympus, Kadoc investigates Kirschtaria’s research, including Ophelia’s broadcast when she informs him Skadi remembers the moment they got pruned, and then, suddenly they were not. And had a good thousands of years old history filling the gaps as if it was always there. Then you learn Kirschtaria went through a version of Part 1. Seven times. To bring his friends back to life. This is what we called a simulation, and possibly related to Olga’s what-if ‘visions’ in Lostroom, where she is a Master (of evil aligned Servants).
Avalon Le Fae wraps this foreshadowing with Morgan clone mocking Guda for not figuring out the purpose behind Chaldea’s Rayshifting and other things, already making the players aware of a confirmation of Chaldea’s equipment involvement. Whether intended by the Animuspheres, this is yet unconfirmed, it could be very well an unwanted consequence like the Taint of the Greater Grail after the Third Grail War. We do know Flauros called them lunatics and targeted Olga specifically. This was dismissed a gratuitous evil character moment, but he’s a character Nasu wrote this scene about a year before FGO launched. There has to be a reason for his behavior. Rasputin exposes their childish dreams will be over with the attack on Chaldea, therefore it may be unintentional.
Why are the trees so important? This is why:
We are simulations projected by the Tree of Fantasy in a 'what if' world.
In other words:
What originated in a Lostbelt (Fantasy) cannot live in a Singularity (Reality).
This is the context of what Ash Tree Savior and Totorot need to be Morgan and Habetrot, because they would disappear as fantasy when the calendar changes to the Queen’s Era.
The entire chapter is a criticism of regarding inconvenient answers as fantasy, discarded and conveniently forgotten as if the feelings and people who lived there weren’t “real” and none of their grief mattered. With Oberon furiously denouncing Panhistory’s monstrosity. In a way criticising the modern’s fiction consumerist too, no doubt part of Nasu’s theme for Second Phase Type-Moon. Also boils down to a human system (materialised in Panhistory and their pruning mechanism) that is predatory against everything, including the planet and other people. This competition.
But rest my case why they should have stuck with “Fantasy” instead of “Emptiness.” Because they are talking indeed of trees which regenerate and create history from a pruned end and takes this “fantasy” and makes it “real.” It’s more or less how Type-Moon works. No matter the source, everything, including the Panhistory texture, is materialised data.