“存在的地平线”，博识学会通常将其称为“虚无视界”，意指它是存在与虚无的边界。这种间隔界线不属于物质层面，而是概念意义上“现实的尽头”。
虽然该视界是非物质的，但部分学者称，受“虚无”Ⅸ及其命途影响的自灭者能够观测到虚无视界，状如恒星发生全食现象时的形貌；另有研究对此持相反意见，他们认为当该视界如同黑暗的太阳高悬于某人眼中时，便意味着一名自灭者就此诞生。
尽管各执一词，双方还是在一点上达成了共识，即：虚无视界会且仅会与观测者产生相互作用。换言之，一旦某人观测到虚无视界，便无法停止这一行为，且会不可逆地向着视界边缘靠近，断无逃离的可能。一些对“虚无”充满兴趣的学者猜测，自灭者或受其影响的世界将坠入其中，其存在会被永恒固定在不可观测的视界对侧，从现实中抹除。
【记录印戳】“只有自灭者能够观测”，“落入其中的人无一能够复返”…这些结论难以证实或证伪，或有可能出自虚构史学家的杜撰。
The Horizon of Existence, often referred to as the Border of Nihility by the Intelligentsia Guild, marks the boundary between existence and nihility. This boundary does not pertain to the material realm but signifies the conceptual "end of reality."
Despite the intangible nature of the border, some scholars argue that individuals affected by IX the Nihility and THEIR Path can actually perceive the Border of Nihility, akin to witnessing a total eclipse of a star. Conversely, others suggest that when this border rises like the darkened sun and reflects in one's eyes, it heralds the emergence of a new Self-Annihilator.
Despite this divergence, both sides agree on one aspect: The Border of Nihility solely affects its observers. In other words, once an individual has observed the Border of Nihility, they cannot stop this behavior and will irreversibly move towards the edge of the border, with no possibility of escape. Scholars intrigued by the Nihility speculate that affected Self-Annihilators and affected worlds will plunge into the Border itself, with their very existence eternally fixed to the other side of the unobservable Border, ultimately eradicated from reality.
Record Stamp: "Only Self-Annihilators can observe the Border." "None of those who were drawn by it have ever returned." ...These conclusions remain challenging to verify or falsify, potentially fabricated by History Fictionologists.
