Academy of Familiars. The Secret of the Dark Past

“The Secret of the Dark Past” is a fantasy novel by Lina Alfeeva, the third book in the “Academy of Familiars” cycle, genre: heroic fantasy, isekai.
Yesterday you were just a boring study-ahead bookworm, a quiet girl from a closed world—and today they consider you the academy’s most promising student of familiars. Adventures cling to you immediately: your future mother-in-law is plotting against you, and your fiancé might turn out to be a potential ruler of a world that hides ominous secrets. But when there’s a mage-isekai girl from Earth nearby, and behind your back stands a company of faithful friends, nothing is scary anymore… even the whispers of the dark past.