The light novel Lord El-Melloi II-sei no Boken, a direct sequel to Lord El-Melloi II-sei no Jikenbo, has a defined fate. Author Makoto Sanda confirmed that the series will conclude with volume 13, marking the end of this phase within the Fate universe.
According to the author himself, the draft of the final volume is already in production. Furthermore, franchise creator Kinoko Nasu has revised volume 12, indicating that this stage of the story has already been completed and is undergoing final adjustments before release.
Lord El-Melloi: A direct continuation of a spin-off.
The plot follows Lord El-Melloi II, the adult version of Waver Velvet, a character introduced in Fate/Zero. As a professor at the Clock Tower, headquarters of the Mage's Association in England, he investigates cases related to the magical world alongside his apprentice Gray.
The sequel was released in 2020 with illustrations by Mineji Sakamoto and expanded the universe presented in the original series that began in 2014. The project also received an anime adaptation, Rail Zeppelin Grace Note, which aired in 2019.
Closure reinforces the project's cycle
With volume 13, the story should conclude the main mysteries surrounding the Mage's Association and the central characters. Finally, the franchise also has manga published by Kadokawa.
Source: X @makoto_sanda