Not a man.
Obviously. A (hu)man is not a super-powered alien threat to all life on earth who will not stand down. That's a being who will only be stopped by death. This is not the Super Friends.
"Super-powered alien threat to all life on earth who will not stand down" of Steel and Super "super-powered alien threat to all life on earth who will not stand down" just don't sound right to me, though.
Also, didn't Man of Steel hint at shared ancestry? That and the ability to reproduce with us (what separates species from each other) brings them as close to being "man" as any of us, really.