"Not wanton killing, but a judicious slaying. The point is, they know there is an Invisible Man—as well as we know there is an Invisible Man. And that Invisible Man, Kemp, must now establish a Reign of Terror. Yes; no doubt it's startling. But I mean it. A Reign of Terror. He must take some town like your Burdock and terrify and dominate it. He must issue his orders. He can do that in a thousand ways—scraps of paper thrust under doors would suffice. And all who disobey his orders he must kill, and kill all who would defend them." (24.28)
What's the point of violence? For the Invisible Man, it seems like violence is often just a hobby or a fun activity. Here, though, he lays out a plan. He'll only use violence in order to get what he wants. In other words, violence here is a source of power.
"The fact is, I'm all here—head, hands, legs, and all the rest of it, but it happens I'm invisible. It's a confounded nuisance, but I am. That's no reason why I should be poked to pieces by every stupid bumpkin in Iping, is it?" (7.50)
The Invisible Man is being attacked by the people of Iping and has just agreed to surrender to the police. (Turns out he's lying, by the way, which also shows us a lot about him.) When he finally reveals his identity, he also takes the opportunity to distance himself even more from the villagers by calling them bumpkins. This guy <em>really</em> doesn't want to make friends.