RC’s acceptance system might be something of a mystery still: Malleus was presumably already one of the world’s most powerful mages prior to NRC, while Riddle was already at the top of all his classes.
It seems like these achievements would have influenced their selection by the Dark Mirror, except: they both attend NRC alongside students like Ruggie, who describes himself as “a middling mage.”
With students like Deuce and Epel it is clear that NRC admittance is not exclusive to financially stable families, but it is also not based on past academic achievement, with Silver, Ruggie and Lilia never attending any school at all before they received their acceptance letters.
This seems to narrow down the pool of potential students to “must have magic,” and Lilia says, “A person has to have some magical ability to enroll at Night Raven College,” while Crowley explains that students must have “a talent for magic” and “a rare aptitude for magic.”
“Rare aptitude for magic” is a little vague, with objectively weaker students like Kalim and Ruggie studying the same curriculum alongside talented mages like Azul and Riddle.
According to the novel magic is special even in the Twst universe, with a ghost explaining to Yuuya that only one in ten humans can can use any magic at all, and that is usually “real small stakes” magic like the ability to move a cup onto a table or light a fire without a match.
The ghost says, “It’s a rare one who’s got enough magic to get into Night Raven College.”
(Disclaimer: the novel and game have so many differences between them that something being canon in one does not mean it is also canon in the other, but there has also been nothing in the game to disprove the ghost’s claim, so it is not impossible that this world-building is canon to both.)
But Malleus and Idia have commented on how everyone’s potential for magic is unlimited (more here) regardless of someone’s inherent talent for it, and Riddle is living proof, so would even a “move a cup” mage be a candidate for enrollment?
What is the differentiating factor between who is good enough for NRC and who is not, if all mages share the same potential for greatness?
And there is also Deuce’s comment in Book 5:
When Kalim reveals that he received his letter of acceptance a year after school had already began, he asks, “They belatedly recognized the nature of your soul?” while Ace similarly says, “I thought Night Raven College only admitted folks whose souls were chosen by the Dark Mirror.”
And “the nature of one’s soul” is a conveniently vague condition for admittance.
Concerning the catalyst for NRC’s acceptance letters is, it is possible that we have been given no information at this time.
Kalim says that he just “suddenly got” his letter of acceptance, and while we have heard mentions of this letter from Deuce, Silver and Sebek, no one ever mentions applying.
Lilia’s letter arrived 500 years in the past and it seems he was insulted by it: there is no hint that he ever wanted it at all.
The same goes for Leona, with both characters ignoring their letters only to enroll belatedly later on, after Lilia became a very different person from who he was when his letter was first received.
The current student selection process was introduced 100 years ago. Did the school always rely on the vague requirement of “the nature of one’s soul,” or did there used to be additional/different conditions that needed to be met back when Lilia received his letter?
Are rules for admittance being kept intentionally unclear so that someone might be able to create certain circumstances, such as having the school attended by certain overblot-susceptible-students at the same time, in order to accomplish something yet unknown? Maybe not, but also, maybe? It is all theory and conjecture at this time.
Twisted Wonderland Reference Note 