not entirely sure how it would work, but maybe someone tfs "into" the Castle itself? like it assimilates them and now their consciousness pervades it. might be really useful for playing tricks on other headmates...
The Castle already exists, so this’d be kind of an absorption tf, I guess? Not my favorite kind…
The effect, however, would be kinda interesting. Being able to mess with people inside would be fun! The only problem is that Lápiz already has this power by writing reality as a story :P As long as the setting is the Castle, someone being the Castle would effectively be the same as being Lápiz!
Actually Lápiz would probably be way stronger… She could just kinda write “you change back now” and it’d happen o~o
Heaven’s Door moment tbh