The Portrait of What Looked Like A Large Pile of Ash is an Artifact of Doom causing all of the weirdness
Voldermort made it to mess with the wizarding world. The story is an alternate retelling of Harry Potter and the Deathly Hallows
The gang are Storming the Castle that's been overrun by Voldemort and Death Eaters. "Clumping happily" is a colloquialism.
To do so is to get along - Hermione is trying to keep Harry and Ron from being stupid using threats of violence.- That makes a little too much sense for this story.
