Honestly, the hardest part of replaying it was speedrunning Human to get the last piece of game clear artwork. There is such a thing as 'too easy', especially right after beating DMC 3: SE on DMD. That's when I noticed that Devil May Cry 4's DMD doesn't really touch 3, but it's still plenty hard. Just not 'take several days' hard.
Surprisingly, Legendary Dark Knight was the mode that caught me off guard. I don't really record my gameplay, but a run of Mission 17 on LDK would be a good one for anyone interested in showing off, I'd say.