Dante has three styles of fighting--human, angel, and demon. They were all on display in that video, and they're done by holding R1 and pressing/holding a single button, seemingly. It's been very simplified from DMC3 and DMC4. Also worth noting was how easy it was for whoever was playing to maintain S rank combos. I'm sure for some people it might even look more appealing, but I have a very high standard with DMC, so the more gameplay I see the less enthusiastic I am about the game. I was originally pretty forgiving, too.
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"When I was a young man, I had liberty, but I did not see it. I had time, but I did not know it."