Life Circles, Light Circles, Light Cycles, or Life Cycles. (Interchangeable)
They can both be used to describe the phenomenon that resets the world every 50.000 years, and each period in-between. It is however, most commonly referring to the latter.
The phenomenon that resets the world is a sort of meteor or comet, created by the Gods of Time, Life, and Death, to keep the Goddesses of Creation and Destruction trapped at the center of the planet in a dormant state. The meteor is in a constant time loop, to ensure its continued return even after being destroyed.
The approach of the meteor creates strange chaotic phenomenon; most famously weakening the dimensional barriers, trapping several people in the first Death Realm. It is also known to produce green lightning and once turned the sky black right before its impact.
The elemental Gems of Earth, Air, Space and Chaos are the only things shown to be able to negate its power.
The meteor was destroyed before hitting the planet in the DragonSoul universe, which therefore continued its existence for another 50.000 years.