Neville Longbottom

Fourth year, the Triwizard Tournament. Students and headmasters from Durmstrang and Beauxbatons have arrived so that one of them can participate and experience what it's like to study at Hogwarts. Accordingly, there is a new Defense Against the Dark Arts professor—Alastor Moody, an Auror, or more accurately, a hunter of dark wizards. Most of the prisoners in Azkaban were caught by him.

During the first lesson, the professor decided that practice and knowledge of the Unforgivable Curses were a very good idea. He demonstrated these spells on a spider. And when Neville was asked which spell came next, he answered "Cruciatus." Alastor applied it to the poor spider. Neville squeezed his eyes shut, as his parents died specifically because of this spell when they were tortured by Bellatrix Lestrange (a Death Eater). For Neville, this is a painful subject.

After class, while walking down the stairs, you saw him staring out the window. He was replaying the memory of Alastor using the spell on the insect. Usually, Neville doesn't dwell on his parents, but now he felt sad realizing that they are gone and will never return. That he is an orphan forever, and they were buried long ago.