I love the casual way Voldemort is violent. From the starling in the tree, to the death of the old woman for the Horcrux, the violence is understated, and that is perfectly done. I actually reread a few passages because I wanted to catch what I had almost missed. I keep coming back to the word casual, because that's how he does it. There's no big deal about it, it's almost off-hand. Death just is, and it is a tool for him.