Light Novel Volume 14

Summary
Life goes on, so does Rudeus's. Rudeus is acknowledged as the big boss in the school and many legends about him are spread through the school. However, Rudeus does not care about those legends at all, he is living his life peacefully or so it seems. He attained the rank of Water King Rank magician in these peaceful days and married Roxy, gaining a second wife. Time passes while one is not paying attention, yeah I`m talking about graduation. Rinia and Pursena Adorudia graduated from school and then had a duel to decide who will be the tribes chief in the future, long story short Pursena won. Experiments for Nanahoshi's return are continuing, but her health is getting worse, what is going on?

I'm not sure because whoever wrote this summary did a fucking terrible job.