Keira Espada tells her underclassman Salacha Shicksal that she’d rather an inter-family fued like the Angels’ not interfere with the Luna Lumiere Selection Tournament, but there’s nothing she, Melida or Elise can do about it. White Night’s ongoing investigation into Melida’s ability and Othello’s insistance on Elise’s superiority means there’s no way the tournament won’t be affected. Indeed, it already has.
That’s thanks both to Othello’s rigging of the cadet selection and the fact that Black Madia is not only on the loose in the school, but assuming the form of a student, meaning she is everywhere and nowhere. Still, the host school’s headmaster would apparently prefer both a tainted final result and the mortal danger of a lurking assassin rather than cancelling or even postponing the tournament. She puts tradition and propriety before truth and the safety of her students. Shame on her!
Anyway, the show indeed goes on, by which point Melida has been encouraged and galvanized by both her tutor Kufa and her teammates Nerva and Shenfa, who buck the trend of believing Melida will never measure up to Elise. When the two finally meet for the fateful duel, Elise finally expresses that she didn’t want to win against her “big sister” because she didn’t want everyone’s assumptions—including her own—that Melida was weaker than her to be true. She wanted to continue being second-best.
Deeming that to be impossible to keep up the charade any longer, all Elli can do now is prove that which everyone assumes and which she always feared: that Melida can’t beat her. Only…Melida hasn’t been sitting idle all these weeks with Kufa. She’s learned quite a few new tricks that optimize her mana, and Elli has been too busy with her own preparations to keep up with her big sister’s training.
Turns out Melida not only believes she can beat Elli, but she goes and does it. With everyone watching, Elli doesn’t take the fall, she loses fair and square to a disarming attack, and Melida makes it clear she’s determined to stay a step ahead of her little sister…if only just a step.
While the sisters’ fight didn’t last long, it did pack a punch, and I appreciated that Ishikawa Yui got some spirited dialogue to sink her teeth into, almost channeling her best-known role, Mikasa Ackerman, in the process (both Mikasa and Elli both being cool, powerful, yet reserved beauties).
As they fight, Kufa is on the lookout for the disguised Black Madia, and thinks he’s found her when he encounters her all alone with something suspicious in her bag. Turns out he’s mistaken: it’s not Black Madia at all, but a student from the other school who spoke with Melida last week: Mule la Mor. Her mana-absorbing Diabolos class is too high a class for Madia.
Soon after Melida and Elise’s big catharsis, Madia steps in to try to finish the job Kufa won’t on behalf of White Night, who disguised herself as Nerva to get as close as possible to her target. The glass palace’s giant sentries initially stops her, but she destroys their weapons. Turns out that’s an unforced error, as it allows other non-cadets to enter and save the day: specifically Kufa, with Rosetti backing him up.
Kufa slashes away all of the Clown-class’s illusions until she’s stripped down to a revealing outfit that makes her self-conscious. At this point she completely loses her nerve and becomes submissive to Kufa, almost acting like she likes him, which may be the case. In any case, Kufa suggests a compromise: she can return to their boss with his “supplementary report”, thus not returning empty-handed in shame. In exchange, she’ll withdraw without further trouble.
After the credits, however, Madia is right back at the school, this time entering the front door as an instructor. Her transition from fearsome adversary to potential ally and supporter of Melida is awfully quick, but I’ll allow it. As for the tournament, Keira Espada wins, and Mule la Mor shows Salacha Shicksal a “mana analyzer” containing all the mana info of every girl who fought in the palace—including Melida’s—for Salacha’s brother. As the OP hinted, looks like we’ll likely see more of Mule and Salacha.