Satan

It's a bit hard, and I have to bite my lower lip, to avoid ridiculing the Satan idea.  He has, however, over the centuries, gotten a lot more sophisticated -- he no longer has horns and cloven hooves, for example, and in Victorian literature tends to carefully pick out his targets as people of intelligence and talent who appear to be particularly desirable souls, much as we pick out a ripe red cherry.

As a literary device, then, he is great, especially if you want to deal with aspects of human existence and desire and ambition and pride.

Now, though, really -- get real.  Such a figure would long ago have given up, since he knows he is otherwise doomed.  Be rational folks -- and this bit about Satan wanting to convince the world he doesn't exist is just a remarkably stupid rationalization -- conflicting with his supposed pride.  Why should he care to bring others down to perdition?  What would it be to him since he's doomed anyway?  You have to break through the childhood indoctrination and think about things a little.