Soo...... we have two fangirls (or a fanboy) over Silent Witch and her complex magecraft... Honestly if the secret does get out, at the very least, he can gush about it to Isabelle AND Monica :>
And you know it'd be even more awkward since he kind of belittles Monica, calling her a squirrel and his pet and all that... so like if he finds out Monica is the Silent Witch....................

Also gotta mention my obligatory Isabelle best girl :3 I totally want to see the sleepover that she's been waiting for! I've been waiting for it too! Isabelle totally deserves it after all she's done for Monica!