Agree, make DT like it was in previous games. If they ever did a sequel, I don't think they will...
1. If they did, I would like to see a better DT. Don't give me a press to win button, give me something that slows down time, but I have to earn the chance to slow down time. For example in DMC2, the Chrono Heart would slow down time only when I hit an enemy. The effect would only last about 2 or 3 seconds, after that the effect wears off. Therefore you have to keep using your skill and your speed to trigger the time dilation effect. This is very similar to how time dilation works in Bayontta. So give me time dilation DT, but make it so I feel rewarded everytime I activate time dialtion so it feels like proper game mechanic rather than a win button.
2. Bring bank DMC3s' special super finishers. The finishers looked great, okay functionally they didn't work that well in DMC3, but get it right, like for example Bayonetta 2's awesome finishing moves, and the game would be nearly perfect. Maybe one of those finishing moves could also slice enemies in half (MGR), that would be a nice touch.
3. To make DmC perfect, and I mean perfect, you need to do the above points, but lastly you need to have a lot more moves in the game. I know we had most of the classics, but what about Shotgun Stinger (****ing awesome move), or Nero's Dive/Drop Kick.
The only final thing I can add is Parrying. I don't know if I sucked at Parrying, or if it was too risky to use it, but how about more use of the Parrying mechanic. Like for example what about a boss that can only be defeated by Parrying its attacks back at it. Like a dopplegangger mirror fight (DMC3). This is linked to point 3 really.