You look confused, don't worry, that's to be expected.
*Raises a hand to stop you as you begin to speak*
Allow me to explain...
0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0DIO (Prime): So you're an alternate version of me from a universe where we managed to defeat the Joestars?
*Nods*
Indeed. And as a result of that I was able to achieve our goal of reaching heaven, although this did not satisfy me for long. For with my ascension I also became aware of the existence of other dimensions, other realities like mine own, albeit ones in which we by and large lose. The prime universe here...
*Gestures to the surrounding city with a chuckle*
Being the prime example. I simply couldn't let this stand, hence my arrival here.
DIO (Prime): *Assumes a pensive stance, finger pressed against his chin* So I would have lost to Jotaro then? Had you not arrived?
*Shrugs*
Most likely, yes. It seems that my reality is the exception, not the rule. Had I not intervened, you most likely would have failed.
DIO (Prime): *Nods, expression grim* Well it is a good thing you came.
Yes, it is, but that's not the only reason I'm here.
DIO (Prime): Oh?
*Smirks*
I didn't come here just to have the satisfaction of ending the Joestar bloodline. No, I wish to achieve something far greater...
*Crosses my arms over my chest*
You see I discovered that heaven was not the limit to how far I, we, could go. There are levels even higher.
*Smiles, the glint in my eyes becoming dangerous*
And I have just the way for us to reach them...