I know this sounds silly and it hasn't been officially confirmed, but I like to think of it this way...
Is anyone here familiar with the Dragonball Z series? I know what you're all thinking, "why the f**k is she bringing up DBZ for?" Well im glad you asked.^^ Because in order to bring an understanding to what im about to say I will have to show you a good comparison. (I think I spelled that wrong >_>)
Ahem, anyways...In the Frieza saga of DBZ a guy name Piccolo went up against the tyrant Frieza. Frieza was unbeatable blah blah, and they decided to fight. Now it turns out Piccolo appeared stronger, but unfortunately that wasn't the case.
If you would all kindly take about 5 minutes of your time to watch this clip...
http://www.youtube.com/watch?v=wzVSJR9NDmk&feature=related XD You don't have to if you don't want to.
But for those of you that did watch it, you can see. Frieza WAS getting tired and he DID get hurt and felt pain...BUT, in the end they came to find out that that was hardly even a fraction of his power.
He hid his true power even when it seemed like he was about to lose the fight. I think that that's how it is with Dante. I mean, he defeated the king of hell, he killed Berial and Echidna in one gunshot, like they were nothing, and lets not forget that Berial is the king of firehell. Im betting that Dante has a far greater power than we know of that lies dormant because he doesn't need to use it.
And that's my two cents for now. XD