Standard Branch
The Supracosmic External Barrier (SEB) is a wall that surrounds the Supracosm to protect it from being exposed to the PTSS. The SEB prevents entities within the Supracosm from exiting it, and also prevents the outside pressure from the PTSS from crushing the Supracosm, erasing all entites and realms within it. The SEB formed a short time after the creation of the Supracosm.
While the SEB is an extremely powerful and effective barrier, it eventually wears out as it grows older. So, at the beginning of every AESY, the worn-out layers of the SEB instantly disintegrate and get replaced with new, healthy layers that will allow the SEB to continue to withstand the pressure of PTSS.
During this instant moment, the Supracosm is exposed to PTSS, which can cause slight or major changes in the Supracosm's environment. Occasionally, entities get sucked into the vacuum of PTSS, never to be seen again. Also, there can be changes in the laws of reality within the Supracosm.