Well for one thing, I'd probably have made it exactly like it was for DmC, but instead of rock, I'd focus more on rap music as a backdrop along with punk rock. As for the story, I'd keep it more or less the same of just killing demons who have ruled the world from behind the scenes, only on a more Hellblazer scheme with less demon propoganda and more demons raping human beings to give birth to antichrist spawns. Dante would be more darker and more cynical then he is in DmC in that despite him being harsh as hell and raw as ever, he'd be a humanist. I''d also have him cursing more then what was in DmC to express his anger for demons in general. I'd also add Vergil in there but not as the leader of an Order but as a part of the problem by being a rich tycoon who was questionable on which side he'd be on. Kat probably would be renamed but her purpose would still be the same. She'd honestly be more sexier and a gothic-like attire, but I'd do a hell of a lot better at making her a better female character then how DMC whores their females. The demons would also be alike, but Mundus would look more like a big tycoon with the fur coat and smoking a cigar. I'd have more blood, more gore, more horror, while still keeping the comedy, dark humor, and action.
Dante wouldn't be dressed in that lame anime crap like in DMC, but a more western punk/grunge style. Mostly a leather coat with a bit of red accents with a detachable red hood , leather jeans, and combat boots. The works. His hair would be black and in the same fashion as DmC now but there'd be that white patch in the back of his head from the beginning. He'd obviously smoke as a way to calm himself down from releasing his true powers since he thought if he didn't, he'd go crazy. A bit of facial hair wouldn't hurt either.
Vergil would be dressed in a black film noir-like trench coat with a bit of blue accents to it. He'd have his hair the same as it is in DmC now and he'd be wearing white gloves because he refuses to touch anything that's human related. Cause he'd be a douche like that.
Kat would dress like a girl trying to be grunge and tough but only coming off as cute. This is of course if Kat came while in the beginning of development.
I would destroy anything that fans held dear of their old DMC and rip it apart to make way for my action, griddy, and action filled DmC. No corny one liners, no bishonen bullshit, no anime cliches, no Nero, etc. The hack n slash comboing, the white hair, and the "jackpot" line would still be there, but other then a few other things, that's it. I'd turn my back on DMC and forget it existed once I have what I want to add. I couldn't care for the past. Only the future. Course I wouldn't say that out loud.
- The difficulty would be cranked up higher then even DMC1 where if you can't counter at the right time or use the right weapon (which you'd have to figure out for yourself) you lose and have to start right from mission 1 again. But this is only on DMD mode. No pain, no gain.
- There'd be DLC costumes for both Dante and Vergil
- No items can be cared with you in missions during DMD
- no holy water in DMD
- no gold orbs in DMD
- your attack power is slightly cut in half in DMD
- you only have a beginner's amount of health for DMD
- if you get SSS on every mission of DMD, you unlock bonuses like character creation, and all that.
- Bloody Palace goes up to 1000 rooms
- to win Bloody Palace, you must beat DMD.
Yeah, I assume you'd imagine my DMD being brutal.
The world would be a mix of urban streets and cities mixed with gothic modern cities as well. Something like Gotham in Arakham city but with mostly with the sun up. Limbo would still be a factor to control the world shifts and such and demons appearing.
These are just what come off the top of my head though.