True owner
The artificial rift in which their test took place had a vast forested area of tens of thousands of kilometers. In the first day that they spent in the continuous monster hunt, they didn't even come close to exploring even 1 percent of its entire area.
The rift recreated the perfect change of day and night and even had its own sun and moon. And it was not limited to that, as almost every detail here was elaborated and seemed indistinguishable from the real world. Moreover, there were hundreds of thousands of artificially created monsters and plants that needed to be energized from time to time.
And after all, this was only a D-ranked rift, above which were higher ranked rifts with even more complex structure and even stronger monsters.
One logical question arose from all this.
Where does the academy get the spare resources to create and maintain all this?