This video just shows an area I grinded alot in the previous video. You should recognize it when you get to it, or in my previous video. Its the last area shown in my previous video. I probably wont show more grinding areas but they are easy to find. You can usually find areas with a few easy enemies that you can keep respawning by moving around the screen. You dont have to leave an area completely to respawn enemies.
These are the type of areas that are good to grind. You will always have an opportunity before each boss to grind before trying it again. Its one way to stay alive. This extends to the final boss.