A good way to do this one is with Nite Owl. I played through the game to gather abilities first. Once you have the abilities, you can use your Electric Nite Owl Charge to keep yourself safe throughout.
I did the first level and just spammed R1 and Square during fights to continuously counter attack. When I would come upon large groups, before going to those spots I would let my charge ability fill up so that I could shock them all right away then beat them down quickly.
You can actually just mash both R1 and Square at the same time, you don't have to bother with timing. The only trouble spot to watch out for is the room that is on fire as the fire can and will hurt you. Be especially careful.
Other than that, I got it 2nd try.
Another method is to do it during a co-op game: Make sure you are controller 1 as nothing that controller 2 does will aid your stats or reward you trophies. You just let your partner fight off all the enemies and stay back and safe. You can also do this method in the single player game and let your AI partner do all the attacks. Again just stay back.