It wasn't Mundus who outlawed it, they existed before but were hunted for being a threat to both heaven and hell. The fact that they were hunted and extinct for potentially being too powerful says it all. How would being half human be an advantage as opposed to half angel?
They were hunted to extinction by Mundus' forces because he feared them, and he outlawed the mixing of the 2 groups to stop any more being born. There were angels there when Eva died, none of them saw fit to murder Donte.
How is being half human an advantage in the original series? Logically it makes no sense. It's constantly shown in DMC that even the most powerful humans are only able to take on the very bottom tier demons, yet Dante embracing his humanity allowed him to defeat his clearly superior twin, toy with extremely powerful demons and even kill the demon king. Logic.
That being said the whole "angel/demon hybrids are the only thing that can kill Mundus" thing was stupid anyway. If that's true then why the hell are angels even bothering to go to war with the demons? They may as well just align with Mundus since
they can never defeat him.
On topic, but slightly off topic:
Vergil>Vorgel>Dante(DMC3)>Donte>Nero
Going by feats of power/skill displayed that's how I'd rank it. Now obviously Dante/Donte have to win because they're the protagonists, but consider this, both Vergil incarnations are; better swordsmen, better with magic, more adept at using DT, and more knowledgeable about the supernatural than their respective Dantes. It's the Star Wars syndrome; the one that should logically win has to lose, because storyline.
DMC4 Dante would of course knock all of them out, probably at the same time, at which point DMC2 Dante flies in and nukes everything with his ridiculous super-DT form and then goes for pizza, which he orders in sign language because talking isn't cool :tongue: