In the years 174 N.C. and 234 N.C., two separate groups of people were researching the Eternal Life Machine. In their respective time periods, they activated this massive Space-Time Instrument, and the resulting burst of temporal energy resonated along the timeline, forcing open a Space-Time Tunnel.
The first activation probably didn't last long, only causing his transmigration. This, however, was the second activation—undoubtedly the time for the Spirit of the End to execute its plan.
The Spirit of the End first spread its corruption in secret, causing Nightmare contamination to erupt from reality itself. This allowed the Spirit Realm to gradually merge with reality, greatly weakening reality's "barrier." After that, the Eternal Life Machine was activated for the second time, and the Time Tunnel opened. The now-vulnerable reality, riddled with holes, could not withstand the surging temporal torrent. And so, the future descended.
