Lost World

A is a Lostbelt with the same strength as Proper Human History due to no longer being a "fantasy" and instead becoming "real". The only known example is the British Lostbelt.
==Characteristicts==
In the case of the British Lostbelt, it became its own Proper Human History by virtue of killing its Fantasy Tree, using its Magical Energy to turn the Lostbelt into a Singularity, and sustaining the Singularity through different means - turning a Fantasy into a Reality.Fate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Section 29: A Prophecy Morgan le Fay achieved this by Rayshifting within the Lostbelt itself, sending her information on Proper Human History and the future of the Lostbelt to the version of her within the Lostbelt's past.Fate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Section 21: Lost Will With this knowledge, the Lostbelt's Morgan would survive her own assassination, use Magecraft to kill her Fantasy Tree and cause it to wither, then use the magical energy of the Tree to turn the Lostbelt into a Singularity. Finally she uses the vast Magical Energy in her Summoner's Throne collected from her "existence tax" on the lifeforce of her Fairies to continue sustaining the world afterwards.Fate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Section 2: SalisburyFate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Section 20: Choco Empire EdinburghFate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Interlude I
Because they are as real as inhabitants from Proper Human History, some Lostbelt inhabitants are able to exit a Lostbelt and can emigrate to Proper Human History without disappearing. However, in the British Lostbelt's case, as the humans of the Lostbelt are not natural lifeforms and with no reproductive ability, and were created back when the Fantasy Tree was still alive and history still a fantasy, they remain a fantasy that can only exist in the Lost World. Meanwhile, the Fairies are real and can exist in Proper Human History, as they could be born after the Lostbelt became real.Fate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Section 14: Night Before the Decisive Battle (I)
The reason the Fantasy Tree needs to die for the Lostbelt to become a Singularity is because as long as the Fantasy Tree remains, nothing can be changed in a Lostbelt; any element added causes history to adjust in real-time, even if it isn't consistent. Only when the Fantasy Tree disappears can there be an opportunity for a fantasy to become reality if one can sustain the "world" afterwards. As the time before the Fantasy Tree died is still considered a "fantasy", it allows for an amount of discrepancy, such as sending a Calamity or a person from Proper History back in time, as no matter how much the Fantasy history changes as a result, the beginning of the "real" history when the Fantasy Tree dies is set in stone. Once the Fantasy Tree withers, those time-travelled elements disappear as it contradicts the event of the real history, and inhabitants with memories of those contradictions will revert to the previous version of events without the time-displaced elements. However, if those elements do not make any contradictions in history until they reach the time when they were first sent back in time, they can avoid the paradox and prevent disappearing.Fate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Section 19: OrkneyFate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Fragment 8 Despite this, after history becomes "real", if someone from the Singularity recognises an individual from the Lostbelt as something different to what "real" history says, or an individual from the Lostbelt remembers someone from the Singularity, then the individual from the Lostbelt will become someone who "should not exist" and be erased due to the paradox; memories of that individual will, however, remain.
If the original distortion of history, the origin point and foundation of the Lostbelt, is corrected - in the British Lostbelt's case, the original "Holy Sword" not being forged - then the Singularity will be resolved and eventually the Lostbelt's contents will never have existed without its Fantasy Tree to sustain it. Consequently, should this Singularity merge with Proper Human History, then its history would become part of Proper History - in this case, Proper History will lack the Concept of the "Holy Sword", Excalibur.Fate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Section 26: An EndFate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Section 27: Time of CreationFate/Grand Order: Cosmos in the Lostbelt - Fae Round Table Domain: Avalon le Fae, Section 28: The Moment a Planet is Born
==Known Lost Worlds==
*British Lostbelt
==References==