Oh, it's not human suffering that's enjoyable. [Whenever Dennis taps into these power fantasies, his voice tends to get arch, as if there's an entirely-concocted British accent lurking in the darker corners of his vowels. His bearing becomes very affected, and his eyes seem to fix in his head.] It's the power. You could take their fear away if you wanted to. You could let them live. But you won't. Not unless you want to.

[This is veering into territory that's unsettling Dennis' delicate system, but he can't show that right now, in front of this person who has, according to these monitors, done some pretty intense stuff. It's not just ego stoking Dennis' braggadocio; it's also fear, the sense that the ground is unsteady under his feet, that any second now he could just plummet through the floor.

The best way to avoid that fall is to talk down to someone, even if you have to make it up. Even, especially if, it's becoming increasingly obvious that this person could kill you very quickly and wouldn't even take the time to make it artful. All the murders in Dennis' head are artful. Reality sits outside him, bundled and disheveled, but as soon as it enters his eyes and ears and mouth it has to take off its grubby coat and make itself presentable.

It's the only way to get by.]

Now, you said decades? That's a long time to do something you don't like.