Samurai Warriors 4-II - Survival Mode | Floors 51-80

This is when the stages start to get a bit difficult. Once you get to about Floor 70-ish the game stops messing around and bumps up the enemy's stats through the roof. So much so Nightmare mode in the normal stages are a cakewalk by comparison.

The key to get through this mode is using your items effectively. Particularly, you want to use your Rage Attack to safely deal damage to enemy officers. So you'll want to use your item that refills that and temporarily keeps it at max for when you're in trouble, then use all your other items to help balance out the times it's on cool down.

You pretty much have to do this, because there are no healing items in this. You gain a small heal each time you clear a floor, that's it. Once you reach a certain point, even generic officers will stop flinching from your attacks, meaning there is nothing you can do to not be interrupted by their own attacks. That is why you need to rely on your Rage, Musou, and items to see you through the harder enemies. If all else fails, running around in circles to build up musou is a solid way to fix a poor situation. Especially in this game where you can get a skill that refills your Rage just by running around for a while.