Riddikulus was a targeted spell. It could forcibly transform a Boggart, and only a Boggart.
Otherwise, with third-year students' magical power and control, forcing a magical creature to transform was theoretically impossible.
This was Harry's first encounter with a targeted spell, and he found it quite novel.
At the same time, though, he was curious about something.
Professor Lupin had said that a Boggart would turn into people's deepest fears, and that fear often left even some wizards flustered when facing one.
That raised a question. What am I most afraid of? Harry wondered.
He thought for quite a while but came up with nothing. Just as Harry began feeling cocky enough to think he feared nothing, a black figure quietly emerged from the depths of his mind.
Harry immediately felt a little panicked.
Since the Black Man had appeared during the summer after his first year and bestowed the Left Hand of Chaos and Calamity on Harry, a full year had passed without him appearing again.
If Harry had not still used that ability from time to time, he would almost have forgotten the Black Man existed.
Well, Harry was very, very wary of the Black Man, but as for fear...
That did not quite seem to fit.
After all, at least so far, the Black Man had never done anything that truly harmed Harry. Harry lacked sufficient reason to fear him that much.
For Ginny or Black Ginny, there would have been no need to think at all. It would absolutely be the Black Man, the sort of fear that could make her legs go weak.
After Professor Lupin confirmed that everyone had mastered Riddikulus, he asked them all to think about what they feared most.
That way, they would be less likely to panic when they actually