When Kain returned to his lab on the college campus, he set up the Starlight Bind Barrier, and left Gabriel hooked up to machines that would monitor his vital signs while supplying him with the nutrients he needed using an IV.
He then went about moving into his new room. The first re-ranking of the school year wouldn't be for another few months, therefore the rankings everyone ended with last year were carried over to this meaning—meaning that Kain was still within the top 5 mansion. However, instead of his room being 202, the second-years were placed one floor higher, meaning that he was now in room 302.