I seem to recall that dungeon being an absolute fucker and that I resorted to a guide about thirty seconds in, despite doing most of the other dungeons on my own merits. (Fun fact: I was playing FF4 Advance with the sound muted, so I actually made it to the bottom of the Lunar Ruins and fought the boss without realizing I'd passed any of the challenge dungeons, because I didn't hear the music change. I R COMPETENT GAMER.)