if u wanna base ur arguement on the fact that they're demons, let's break it down like this.....Hulk pretty much owned the world and destroyed like all of the heroes in World War Hulk......of these heroes was Ghost Rider.....Ghost Rider destroyed most of the demons in hell. Of these demons was the strongest, Mephistopiles and Black Heart. Now, when u look at it like that, Ghost Rider pretty much defeated the ruler of Hell, Hulk defeated Ghost Rider, so exo facto, Hulk could kill demons......And these weren't punyh half demons, these were full fledged, full blooded demons.....now, i like Dante....but he wouldn't win....and since this includes Vergil, it's pretty sad when u think about Dante needing help.....and if it looked like Hulk were being defeated, he would be angrier in which he'd be stronger....and if that didn't work, as i stated before, Hulk would call his allies....like Red Hulk, A-bomb, Red She-Hulk, She-Hulk, and Scarr