Belief in The Devil in 2015

[Iroscato]

So we know there are still a large number of people in the world who believe in God and the influence he exerts on the universe, but how many still believe in Satan being the overseer of evil? He seems to be mentioned far less than God in discussions that I've seen, and I've barely seen his name come up even in discussions about Hell.
So, theists, I address this mainly to you. What is your stance on Satan? That you believe in him is almost certainly a given, but how big a role do you think he plays? Do you think he responsible for evil and has a direct hand in controlling evil acts, for example?
How many of you believe he possesses people directly?
And perhaps more interestingly, what do you make of him as a being in and of itself? What do you think are his reasons, his motivations, what makes him tick? Aside from him being Evil Incarnate, of course, I mean what do you think he does day to day, kind of thing. Try to not rely on what the bible says, and muse upon the subject yourselves.
Oh yes. I want you to pick the Devil's brain! *Insert evil cackling here*.