Breather Level

4 vs. Satan:
* The Paralyzing Cave. Yes, the enemies have crippling skills, but if you have Anti-Paralysis items it'd be surprisingly easy for how late it appears in the game.
The Legend of Devils:
* The second castle. It may be long, but despite being supposedly at Level 12, the enemies' skills aren't very strong. The fact you got a third ally at this point doesn't help, even if she's pretty weak at this point, her skills are not.
* The desert. It's one of the few late dungeons where the enemies don't spam devastating skills on the group.
* The volcano. While it's not much easier than the other two dungeons, the enemies' skills aren't that devastating as those of the other two dungeons despite the enemies being slightly more powerful.
** The games starting with 2.0 addressed this and removed some of the devastating, if not outright unfair, skills from some monsters to the "Hard Mode".