Calamity

Overview
The Calamity is a catch-all term for all of the following:
 * The first incidence of abnormal behavior in the Infinite Plane which destroyed 75% of all life in the universe
 * The continuing cataclysmic anomalies constantly happening outside of Habitable Space
 * The inhabitable parts of the Infinite Plane

The Calamity is also known as the perpetual apocalypse or cataclysmic/calamitous space. Extremely occasionally, it's referred to as the danger zone.

Properties
Because the Calamity is a result of the Infinite Plane's actions, its domain takes priority over the domains of most individuals. As such, significant magical power is required in order to defy a cataclysmic anomaly.

Cataclysmic Anomalies
Cataclysmic anomalies are incidents in which the rules of reality become unpredictable and hostile when compared to the conditions enforced in Habitable Space. For example, while in Habitable Space time moves at a rate of 1 second per second, a cataclysmic anomaly occurring might drastically change the rate of time to 1 year per second, dramatically aging those caught in the area of effect and potentially killing them with prolonged exposure.

Exploration
Historically, exploring the Calamity was considered a terrible and dangerous idea.

Shepherd Lluvia Milagro was one of the first to entertain the idea of exploring past the boundaries of Habitable Space in the early years of the Counter Calamity era, hoping to potentially locate more survivors of the perpetual apocalypse. To this end, they formed the Voyager Corps, an organization intended to explore the Calamity.

Though initial expeditions were disastrous, mistakes are for making up. In the present day, Voyagers have developed the requisite spacecraft, technology, and magical techniques to not die near-instantly.

Lingering Threat
Despite the establishment of Habitable Space, cataclysmic anomalies have begun to manifest in areas previously thought to be perfectly safe.

Suffice to say, this is kind of concerning.