To be fair Marvel 3 Dante has a ridiculous attention to detail already. If they wanted to go even further beyond, they could have done wild things like make the QCB moves have Just Frame Cancels that weren't Crazy Dance but instead the uber attacks of the weapon used (like Revolver would become Sattelite [lol Dante with a Haggar lariat...], Reverb becomes Distortion, Jet Stream becomes that rapid battering attack with A&R, the name escapes me right now), RDPs become a thing and you'd add Zodiac, Real Impact and Trick Shot/Ricochet while making his level 3 Dance Macabre instead of Devil Must Die.
Or maybe you could do something with the QCB moves where the idea above is when you Just Frame with S and map a crazy happening to L, M & H like H is Fireworks as it is now, L cancel would be Trick Shot and M cancel would be Ricochet.
There's really no way to implement Doppleganger or Quicksilver in a satisfying non-power up super method without making the entire cast irrelevant unless you balance around Dante at which point the development team would have a tall order on their hands. :lol
Way I was thinking it would be, remove Crazy Dance, turn S into unique specials for each of his QCB moves. Reverb would become Feedback/Crazy Roll and would hard knockdown or something. Revolver would cancel into either Satellite or Flicker. Satellite would probably be better, and it could cause a wall bounce or something. Jet Stream would go into Million Slashes.
RDPs would be Beast Uppercut that can be charged into Rising Dragon like in the games, or further charged into Real Impact which may or may not be an unblockable. Would have the Tornado followup for Real Impact. Then there'd be Trick Shot, which could be style canceled into Ricochet or Sniper. Not sure how they'd work, but I would want it there. Then there'd be Crawler, which I see working like Gamma Wave/Whirlwind in that it's multiple projectiles that come out one after the other and would OTG. Then there'd be RDP + Special, which would be his Royal Guard Ultimate, and it'd probably reflect projectiles or something.
I'd also make DP + Special a thing, and it'd probably be Straight. It'd be kinda like Stinger, except a lot shorter, and maybe make it crumple or stagger. Could be style canceled into Zodiac.
I'd also have air QCBs. One would be an aerial version of Volcano, second would be Nevan's aerial scythe slashes. Either soft-knockdown or hard-knockdown on hit. Maybe soft for first, hard for second? Dunno. Third one would be A&R's cross slash. Would cause a wallbounce.
Devil Trigger would improve some of his moves. Namely Stinger, Reverb Shock, Revolver, and Jet Stream, since those all have 'Level 2' versions of themselves in the games. Stinger would just be faster. Reverb Shock would fire Air Play projectiles like in the games, Revolver would spin more/spin faster, and Jet Stream would come out on block. Also, Beehive would become Hyper Fist in DT.
Koryuu Dante right there.