if ten years ago someone had told me that nagini was actually A WOMAN I would have laughed because of the nonsense of it, but today? after that voldemort-actually-had-a-child-with-bellatrix mess? Today I just shrug it off and consider it plausible
Suddenly, light started shining through the window!
The window, which hanged on the wall, softly letting its curtains dance around the room, suddenly brought a bright light into the house.
Quite unexpectedly, light shined through the window in the room, which was less surprising when you think about the fact that's what windows are for.
Light shined through the window abruptly.
abruptly, usually means unexpected, or sudden. For instance, if your mother picked you up from school after telling you twice about doing that, it would not be abruptly. However, if someone were to tell you your house burned down and your parents were dead without telling you to sit down first, it would very much be called, abruptly.