The Dimension Master was the master of a 3rd dimension. There were many types of 3rd dimensions, and the peak power of a dimension was called the Dimension Master.
In this realm, the dimension itself recognized its master, and only after that could one break through from Tier 26.
But Ethan was not being recognized as the master by the Light Dimension right now; it was the system.
It created a false realm that was as powerful as a Dimension Master, if not more.
Ethan had already covered trillions of realities, and each reality was so far from the other that he was astonished by the sheer size of the dimension.
It felt like eons had passed before he finally became the Dimension Master.
Only after becoming the Dimension Master did he realize that there was a barrier, and no Dimension Master could leave their dimension.
For this period of time, he was the Dimension Master of the Light Dimension, so he also felt the bindings too.
