Devil May Cry 5 Special Edition

Update: Its Dan has pointed out a much better alternative in the comments so I'll put that up here;

"So this method just wasn’t working for me. It was taking me ages to farm this way despite it working very well in the Xbox one version.

I looked around and found this method:
https://m.youtube.com/watch?v=B9CThxwA9jI

It honestly works perfectly and it’s right at the start of the mission. You gain around 400k every 30 seconds.

- Activate your devil trigger so you don’t get knocked out of the animation and use the Red Hot Night skill."

For any one that is struggling or needs an alternative to grinding Bloody Palace. This method also existed in the original release but gives more reward thanks to the ton of enemies in LDK.

What you will need:
• Completed LDK mode up to mission 13 with the original playable characters.
• Dr. Faust upgraded to at least level 3.
• Gunslinger style upgraded to Level 3.

Start Mission 13 and speedrun to the point where you drop down to the area with the Divinity Statue (after popping open two floors). The next area is the key one with a lot of spiked lizards and Antenoras spawning. Have Gunslinger and Dr Faust ready before jump down.
Once you are in the room, all you would be doing is using the Mad Hatter skill which is done by simply pressing B, and then timing another press of the B button as Dante is about to grab the hat. This will cause any enemies you tag with the spin to be affected by the Set Hat skill, and the second press will trigger an explosion that will deal damage and pull the affected enemies closer to you. Repeat until the enemies are cleared out and you should be making a bunch of red orbs. Once the enemies are clear, press the Menu button and Restart Checkpoint to go back to the area with the Divinity Statue and repeat for as long as you need. You will retain all the orbs you just collected and can easily go on another un.

Couple of things to note:
• Quitting the mission will create a checkpoint in the same are, so you can close the game and use the Continue option when you want to start again. If you start another mission, the checkpoint is lost and you have to do the initial part again to reach the checkpoint area.
• Keep Balrog with Rolling Blaze equipped while you are performing Mad Hatter so that your jumps can damage/parry any enemies that might be too close.
• Stay airborne for as long as possible and continue to use Mad Hatter. Try to use Enemy Step to stay in the air, jump back up as soon as you can if you are grounded.
• From what I have checked, Set Hat only affects a max of 5 enemies at a time so you will need to drop just far enough to tag a few more enemies and Enemy Step off them to continue the process
• You WILL still hit. There are too many enemies and Mad Hatter does leave you vulnerable for a while. Don't worry about it, you will be making more red orbs than you lost and restarting the checkpoint gets you back to full life.

Hope that helps, I haven't done the calculations but I get somewhere between 500,000-900,000 per run, sometimes more if I'm lucky.

Video: