Of course it was only in the story because the plot needed it! Most things are only in a story because the plot needs it! And there was plenty of setup for it beforehand–an entire book’s worth in fact.

The fact that it was introduced and then never used again even though it is obviously unbelievably useful and apparently available enough that a 13 year old was lent one to attend extra classes definitely deserves some criticism but at some point you kinda just have to make peace with the fact that it’s a kid’s book and it’s really not that big of a deal.

You’re really doing nothing to dispel (no pun intended) my suspicions that Sanderson readers can’t understand anything that isn’t explicitly explained to them.

Yeah. I don’t think you understand what a deus ex machina is.

She hints at it throughout the whole book/movie by showing that Hermione had a chronologically impossible course load and having her suddenly show up in places that she didn’t seem to be mere seconds previous.

Ok the ghosts coming out of the wands thing kinda came out of nowhere, but all they did was tell Harry to run away. It’s not like they had a massive impact on the fight.

They set it up at the beginning of the movie? How is that a deus ex machina?

Rowling was writing about grade school kids going to school. Grade school kids get bored at school. If they live in a world where everyone uses magic and it’s not that special they’re going to get bored of learning about magic sometimes. It’s like if in grade school our teachers spent a bunch of time teaching us how to use computers, phones, and other technological devices. Sometimes it would be cool and interesting and a lot of the time it would be pretty damn boring.

Plus Rowling wanted the grade school kids reading her books to relate to her characters, so she gave her characters a schooling experience they could relate to. And as much as I hate Rowling, there’s something inherently kind of comedic about a bunch of kids being bored silly learning about magic because it’s something that seems like it should be exciting to us, the reader.

The boredom of the characters isn’t a failure of the writing or magic system, it works perfectly well for its intended effect.

There’s nothing wrong with the magic system because there’s always a reasonable setup and payoff for what can be done with magic and solutions never come out of nowhere as some deus ex machina. The magic system the stories had worked perfectly fine for the stories that were being told. Not every magic system has to be some stupid overly explained BS that takes all of the actual wonder and “magic” out of it.

Rowling is a piece of shit terf but you Sanderson cultists are still so fucking annoying. There’s more to magic in storytelling than just the exact, specific mechanics of how it works. Read Earthsea.